International Review on Modelling and Simulations - Papers (Part A)
Analysis and Simulation of a New Three Phase LLCC Resonant Inverter for Fuel
Vol. 4. n. 1, pp. 1-9
Abstract - In this
paper a new three phase LLCC resonant inverter for fuel cell
applications is discussed. The proposed system consists of two power
stages, which are boost dc-dc converter and three-phase bridge inverter
with resonant tank. The boost dc-dc converter is controlled by adjusting
its duty cycle to supply and maintain particular dc input voltage to the
bridge inverter due to polarization characteristic of fuel cell. The
resonant tank is operated at its geometric mean frequency to achieve
unity voltage gain so that the output voltage of the inverter will not
be affected by load variation. Hence, no external feedback is needed for
the three-phase bridge inverter, thus simplifying the control of the
inverter. The operating principle of the three-phase resonant inverter
is analyzed and Matlab/Simulink simulation is conducted based on the
analysis. The simulation shows that resonance has been achieved and the
output voltage of the inverter is not influenced by load variation.
Resonance technique for the proposed inverter is also shown to result in
Zero Voltage Switching (ZVS). Furthermore, the inverter has very low THD
of output voltage and output current.
Keywords: Fuel Cell, Power Electronics, LLCC Resonant Inverter, Soft Switching.
A New Switching Algorithm for Proposed Multilevel Z-Source Inverter
Vol. 4. n. 1, pp. 10-16
Abstract - This
paper proposes a new switching algorithm for topology of Z-source based
cascaded multilevel inverter. In this topology the output voltage is not
limited to DC voltage source similar to traditional cascaded multilevel
inverter and can be increased with Z network shoot-through states
control due to in switching algorithm the traditional zero states turn
in to shoot-through states sometimes. Besides, it is more reliable
against short circuit. In the proposed topology, each basic unit
consists of one DC voltage source, one Z-source and single H-bridge. In
this paper the operating principle, switching algorithm and
characteristics of proposed topology are presented and performance of
suggested topology in the closed-loop control scheme is described in the
Dynamic Voltage Restorer (DVR) structure. The performance of suggested
inverter and switching algorithm are validated with simulation results
using MATLAB/SIMULINK software.
Keywords: Cascaded H-Bridge Inverter, Switching Algorithm, DVR, Z-Source, Voltage Boosting.
Single-Phase Unity Power Factor Unipolar PWM Rectifier Using DSP
Vol. 4. n. 1, pp. 17-22
Abstract - This
paper aims to apply sinusoidal pulse width modulation (SPWM) technique
to control PWM rectifier achieving by that unity power factor and
reducing the harmonic current of the non linear load. The proposed
control technique has the advantage of reducing switching frequency. The
control structure has been developed and implemented on a DSP
(micro-controller TMS320LF2407). Both pc simulations and experiments
demonstrate the performance of this SPWM scheme in association with the
single phase PWM rectifier.
Keywords: Digital Signal Processor (DSP), Matlab Simulation, Single-Phase Rectifier, Unipolar PWM Modulation, Unity Power-Factor.
Thermal Modeling of Semiconductors in a Three-Level NPC DTC Inverter
Vol. 4. n. 1, pp. 23-34
Abstract - Simulated
junction temperatures of the semiconductor switches of a three-level
Neutral Point Clamped (NPC) inverter applying Direct Torque Control (DTC)
are addressed in this paper. The temperatures are defined by using
simple power loss calculation methods, and the thermal network of the
component is considered as a one-dimensional partial fraction RC
network. The emphasis of this paper is on unequal thermal stressing
between the different components of the NPC DTC inverter. Verification
of the model is based on the use of well-known calculation and
Keywords: IGCT, Three-level inverter, Thermal model.
VHDL-AMS Modeling of the Current Distortions Compensator for ASIC Implementation
Vol. 4. n. 1, pp. 35-41
Abstract - The
latest development of the AC motor control drive is based on digital
implementation of a control algorithm and an important supervision and
control functions as well as; short circuit protection, over voltage
protection and current distortion compensation, etc.
Keywords: ASIC, Behavioral Model, Current Distortions Compensation, DTC, VHDL-AMS, VSI.
A D-Q Synchronous Frame Controller for Single-Phase Inverter-Based Islanded
Distributed Generation Systems
Vol. 4. n. 1, pp. 42-54
Abstract - This
paper deals with the design of a synchronous reference frame control
strategy for single-phase inverter-based islanded distributed generation
systems. Since, the implementation of these regulators requires a
minimum of two independent phases in the system, a second orthogonal
phase is generated using a first order all pass filter. The essence of
the proposed control strategy is to use a SRFPI controller to regulate
the output voltage, together with a simple inner capacitor current
regulating loop to stabilize the system and a voltage-feedforward loop
to improve the system robustness. A detailed design procedure for the
proposed control strategy is presented based on a frequency-response
approach. Practical implementation aspects and the phase margin of the
system are taken into account during the design process. Extensive
simulations confirm the validity of the proposed strategy.
Keywords: Distributed Generation, Single Phase Inverter, Synchronous Frame.
New Hybrid Multicell Inverter Topology with Minimum Number of Switches for a
Dynamic Voltage Restorer
Vol. 4. n. 1, pp. 55-62
Abstract - This
paper presents the Dynamic Voltage Restorer (DVR) based on new hybrid
multicell inverter topology. This inverter is based on a new cell
obtained from the mixture of the two most popular multicell topologies,
Flying Capacitor (FC) and Cascaded Multicell (CM) inverter. The new cell
provides a high number of output levels, high modularity, low number of
components and low losses. The proposed medium voltage DVR is designed
to protect loads at power distribution systems. Simulation carried out
by using MATLAB/SIMULINK software. Simulation results show the
performance of the proposed DVR and prove the validity of the proposed
topology. It is concluded that the proposed DVR works well both in
balance and unbalance conditions of voltages.
Keywords: Hybrid Multicell Inverter, Dynamic Voltage Restorer, Voltage Sag, Voltage Swell.
Vol. 4. n. 1, pp. 63-73
Abstract - In this
study, the grid codes requirements for the connection of the wind power
plants to Turkey’s electric network are mentioned. Recently, it is given
importance to generate electrical energy from the renewable energy
resources in Turkey in order to prevent the foreign-source dependency in
the energy resources and to ensure the variety of resources through a
sustainable environmental management. The electrical energy generation
from wind that is clean and renewable is the most rapidly growing
renewable resource. The installed capacity of wind is expected to reach
to 1000 MW by the end of 2010 and to 20.000MW in 2023. Since the wind
power plants having a different characteristic than the conventional
power plants are disseminated more and more on each passing day, the
existing grid codes remain inadequate for the connection of the wind
turbines to the electric network. The determination of the network
connection criteria for the wind power plants is essential in terms of
the dissemination of the energy generation from Wind in Turkey’s energy
market that has been liberalized after restructuring. The new
regulations are required in order to restrict the negative effects of
the wind power plants on the transmission and distribution system and to
protect the system reliability. In this study, the current regulations
on the connection of the wind power plants to the network are evaluated,
the defects are determined and the recommendations on the new
requirements are made.
Keywords: Wind Power Plant, Technical Requirements, Interconnection, Grid Codes, Turkey.
Improvement of Voltage Unbalance and Voltage Sag in Radial Distribution Systems
Vol. 4. n. 1, pp. 74-78
Abstract - Most of
the dispersed generation systems (DGS) have smaller installation
capacity and have to be connected to the distribution network to supply
electric power into the utility as well as local loads. When the DG is
interconnected in parallel with the utility distribution system, some
operating conflicts might arise that affect the system power quality.
This paper investigate the effect of DG on the distribution network,
with more focusing on power quality issues especially voltage quality
issues like voltage sag and voltage unbalance. To confirm this subject,
simulation results are provided to reveal the effect of DG on power
quality. The purpose of the simulation is to study the effect of
different sizes of synchronous DG on voltage regulation, voltage sag and
voltage unbalance in two cases: without local load and with RL local
load. The simulation is performed using MATLAB/SIMULINK.
Keywords: Distributed Generation (DG), Voltage Unbalance, Voltage Sag.
Voltage Compensation and Fault Current Limiting with Z-Source Based Dynamic
Vol. 4. n. 1, pp. 79-84
Abstract - Dynamic
voltage Restorer (DVR) is applied to optimize the power quality aspects
such as voltage sag compensation. Recently, the application of Z-source
inverter is proposed in order to optimize DVR operation. This inverter
makes DVR to operate appropriately when the energy storage device’s
voltage level severely falls. Here, the Z-source inverter based DVR is
proposed to compensate voltage disturbance at the PCC and to reduce the
fault current in downstream of DVR. By calculating instantaneous current
magnitude in synchronous frame, control system recognizes if the fault
exists or not, and determines whether DVR should compensate voltage
disturbance or try to reduce the fault current. The proposed system is
simulated under voltage sag and swell and short circuit conditions. The
simulation results show that the system operates correctly under voltage
sag and short circuit conditions.
Keywords: Dynamic Voltage Restorer, Z-Source Inverter, Voltage Disturbance, Fault Current.
Transmission Loading Relief(TLR) and Hour-Ahead ATC in Deregulaed Power System
Vol. 4. n. 1, pp. 85-92
Abstract - This
paper illustrates the relationship between Transmission Loading Relief (TLR)
and Available Transfer Capability (ATC), and present possible approaches
to reduce the need to invoke TLR procedures while improving the
utilization of the transmission system. In open-access electricity
markets the reservations of transmission services are based on the data
resulting from the off-line computation of ATC. When ATC data is
inaccurate or misused, security violations can emerge and cause
operators and operation planners to invoke TLR procedures. In this paper
ideas are demonstrated on 7-bus system and results have been presented
Keywords: Hour-Ahead ATC, Off-Line ATC, Transmission Loading Relief (TLR).
Direct Search Method for Solving Dynamic Economic Dispatch Problems
Vol. 4. n. 1, pp. 93-103
Abstract - This
paper presents a simple methodology to solve Dynamic Economic Dispatch (DED)
problems. The main objective is to determine the most economic dispatch
of on line generating units with the predicted load demands over a
certain period of time. The DED is formulated as a second order dynamic
optimization problem that takes into the consideration of the ramp rate
limits of the generating units. The simplified methodology optimizes or
provides the most economic schedule of generation for each interval in
the scheduling time horizon hence the minimization of the total fuel
cost is achieved. The feasibility of the proposed methodology is
demonstrated for solving the dynamic economic dispatch problem with
suitable test systems. The unit operation constraint, prohibited
operating zone and transmission loss are considered for the practical
applications. The simulation results are compared with the recent
reports in terms of solution quality. Numerical simulation results
indicate an improvement in total fuel cost saving and hence the
superiority of the proposed is also revealed for dynamic economic
Keywords: Dynamic Economic Dispatch, Prohibited Operating Zones, Ramp Rate Limits, Sequential Approach, Transmission Loss.
Power System Demand Management Contract Design: a Comparison between Game Theory
and Artificial Neural Networks
Vol. 4. n. 1, pp. 104-112
Abstract - Demand
management in power systems is one of the many innovative ideas
introduced recently for the efficient management of our burgeoning
energy needs. The major aim of demand management programs is to control
an ever increasing demand for electric power among customers.
Controlling customers demand for electric power will bring about load
relief for electric utilities and an overall improvement of power system
security. There exists a wide variety of demand management programs.
Recently demand management contracts have been designed in which
incentives are offered to customers who willingly sign up for load
interruption. In this scenario the incentive offered to the customer
should be greater than the cost of interruption while simultaneously
making it beneficial for the utility. Mechanism design from Game theory
has hitherto been used in the design of such contracts. This paper
proposes a novel idea where an artificial neural network is designed to
select the optimal contract. Our designed artificial neural model uses
the back propagation learning algorithm with useful system parameters
serving as the input and the output the value of the contract. The
results obtained from Game theory using mechanism design are used to
benchmark the results obtained from this artificial neural network.
Furthermore our results show that artificial neural networks are an
attractive option for contract design as they require less computational
procedures than game theory without much of a compromise on accuracy.
Keywords: Artificial Neural Networks, Back Propagation Learning Algorithm, Demand Management, Game Theory, Mechanism Design.
Vol. 4. n. 1, pp. 113-119
Abstract - The paper
presents two developed finite element formulations of the impedance
boundary condition (IBC) based on the variational approach to solve
two-dimensional (2D) eddy current problems, especially at high
frequencies. The first formulation is used in the solution of the eddy
current in a solid circular conductor carrying an alternating current.
The second formulation which is based on the integrodifferential
approach is developed and successfully applied to compute the
resistances and inductances per unit length of both single-core and
3-phase power cables. To show the validity of the proposed formulations,
the obtained results are compared to analytical and published results.
Keywords: Eddy Currents, FE-Formulation, IBC Formulation, Power Cables.
Assessment of Reduction in Losses by Distributed Generation Penetration in a
Radial Network: a Case Study
Vol. 4. n. 1, pp. 120-124
Conventional Transmission and Distribution systems do not envisage at
present any generation on consumer side. However, with the enactment of
Indian Electricity Act 2003 and due to the major changes in the Power
Sector and the fast move towards liberalization of the energy markets,
utilities are inclined to install small capacity generating units to
distribution systems. Integration of small capacity generators at load
points in the existing electrical network will have impact on voltage
regulation, losses, reserve capacity of network etc. In this paper,
Renewable Distributed Generators (RDGs) are introduced at a suitable
location of a heavily loaded distribution network to minimize
distribution losses. Case study has been performed on a real 3.4 MVA
distribution system of a particular area of Gujarat state. A methodology
has been developed for citing the RDGs at a suitable location in the
Keywords: Distribution Losses, Forward / Backward Sweep, Renewable Distributed Generators, Voltage Regulation.
Vol. 4. n. 1, pp. 125-132
Abstract - In This
paper a new methodology for determining the influence of heavy loads
from compact florescent lamps (CFLs) on distribution system is
introduced. Thirty eight samples, consisting of 10 CFL in each sample
were selected for practical test for 15,000 hours operation to determine
the lamps’ performance. New comparison indices were introduced to rank
the CFLs depending on the power system and consumers requirements. A new
simulation model in PSIM simulation program for CFL is used to study the
power quality of the power system for different loading of the CFLs. The
actual simulation model interacts with the variation of the supply
voltage due to voltage drop in the series impedance of the feeders and
transformers. Simulation results show that the power quality of the
distribution system is affected by a high CFLs loads.
Keywords: Compact Florescent Lamp, THD, Power Quality, Distribution System, Simulation Model.
Vol. 4. n. 1, pp. 133-140
Abstract - This work
presents the application of the developed software tool, formed using
the powerful MATLAB® technical computing software and the programming
language Visual C++, which enables the modelling and simulation of
transmission line tower grounding impulse characteristics. Various
grounding models used for estimation of impulse characteristics are
discussed. Special attention is dedicated to the nonlinear model, which
more realistically takes into account the soil ionization influence. The
performed models are convenient for implementation into the existing
programs for the estimating lightning performance of transmission lines.
Basic elements of the software tool are described. The practical and
educational aspects of the software application are denoted, as an
important part for designers applying Computer-Aided Design /
Engineering (CAD / CAE) in Power Systems.
Keywords: Grounding, Modelling, Simulation, Software, Transmission Line.
TCSC Efficiency Assessment in Lines Overload Reduction during Fault Contingency
Vol. 4. n. 1, pp. 141-145
Abstract - In this
paper we initially introduce a method to determine the optimum
allocation of installing one or more thyristor controlled series
capacitor. The target function to determine the TCSCs installing place
is reducing power system lines overload during fault contingency. After
determining TCSCs optimum installation place, their success rate in
reducing lines overload is studied by a new following index,
transmitting index and it is presented that in oppose to our
expectation, TCSCs do not have a great roll in reducing lines overload
during fault contingency. TCSC installation effect on amount of load
shedding reduction is also presented as a new subject to keep buses
voltage stability. IEEE 14&30 bus power systems are selected as the
studied systems and mentioned analysis are applied on this system.
Keywords: Thyristor Controlled Series Capacitor (TCSC), TCSC Allocation, Fault Contingency, Lines Overload, Load Shedding.
Vol. 4. n. 1, pp. 146-156
Abstract - Nowadays,
genetic algorithms (GA) and particle swarm optimization (PSO) are most
famous optimization techniques among various modern heuristic
optimization techniques. Since the two approaches are supposed to find a
solution to a given objective function but employ different strategies
and computational effort, it is appropriate to compare their
performance. This paper presents the application and performance
comparison of PSO and GA optimization techniques, for Static synchronous
series compensator (SSSC)-based controller design for both
single-machine infinite-bus (SMIB) and multi-machine power system. By
minimizing the time-domain based objective function, in which the
deviation in the oscillatory rotor speed of the generator is involved;
stability performance of the system is improved. The non-linear
simulation results are presented under wide range of operating
conditions; disturbances at different locations to show the
effectiveness and robustness of the proposed controller and their
ability to provide efficient damping of low frequency oscillations.
Keywords: Genetic Algorithm, FACTS, SSSC, Particle Swarm Optimization, Power System Stability.
Dynamic Model of a Hybrid Distributed Generation System based on PEM Fuel Cell
Vol. 4. n. 1, pp. 157-163
Abstract - In this
work, we presented a dynamic model of Micro – Turbine Generation System
(MTGS) in grid connected operation. In the second stage, we applied Fuel
Cell in MTGS to improve the system outputs from the view point of
fluctuation of the signals. The dynamic model of the MTGS consists of
four main parts: micro – turbine, PM generator, converter and network.
At first, we considered a dynamic model for the micro – turbine. The
model input signal is rotor speed. and the output of the model is
turbine torque which is a driving force for the PM generator. The
voltage across the stator terminals of the generator has a very high
frequency. A thyristor rectifier rectifies this high frequency AC
voltage to 800 V DC. The DC voltage is inverted back to 50HZ AC by means
of an IGBT inverter, and then filtered to reduce harmonics generated by
the inverter. The novelty of this work is the use of a subsystem based
on Fuel Cell as a DC link between rectifier and converter. We used a
Proton Exchange Membrane (PEM) Fuel Cell stack feeding an average value
800 VDC DC/DC converter. In previous works, a capacitor was used as a DC
link. Comparing to the previous works, which used a capacitor as a DC
link, showed that the output signals of the system improved noticeably
when we used a subsystem based on Fuel Cell as a DC link. The
fluctuation of active and reactive power injected to the grid decreased
very much. Using a fuel cell subsystem had also positive effects on some
other outputs such as current of each phase in line side converter
Keywords: Distributed Generation, Fuel Cell, Inverter, Micro-Turbine, Permanent Magnetic Synchronous Generator, Rectifier.
Optimum Allocation of Distributed Generations based on Efficiency Scores using
Data Envelopment Analysis
Vol. 4. n. 1, pp. 164-170
Distributed generations (DGs) can help in reducing the cost of
electricity to the costumer and promote system technical characteristics
such as loss reduction, voltage profile and reliability indices
improvement. Proper location of DGs in power systems is important for
obtaining their maximum potential benefits. In this paper, a new method
is presented for optimal allocation and sizing of distributed generation
units in order to minimize losses and to improve the reliability index
and voltage profile in distribution systems. Initially, in this paper a
methodology based on nodal price for finding optimum size of DG is
presented. Optimal placement is based on the efficiency scores which are
estimated from data envelopment analysis (DEA). In this research energy
loss rate, voltage profile and expected energy not supplied (EENS) are
considered as inputs and the cost of DG is considered as output for
define a model of DEA to measure the efficiency of install DG in each
bus. The tabu search algorithm is used to obtain EENS in order to
minimizing the outage cost of customer. The proposed algorithm is tested
on a 33 bus test feeder to show the applicability of the method.
Keywords: Data Envelopment Analysis, Distributed Generation, Distribution Networks, Nodal Price.
Demand Side Solution for Transmission Congestion Relief in Competitive
Vol. 4. n. 1, pp. 171-179
Abstract - Recently,
a massive focus has been made on demand response (DR) programs, aimed
for electricity price reduction, transmission lines congestion
resolving, security enhancement and market performance improvement. The
paper develops a method for transmission line congestion management
using demand side approach. In the proposed method the mathematical
model for incentive-based demand response program is developed and in
the next step these market based programs are used as an effective tools
for reducing the congestion cost in the electricity market. The IEEE 30
bus test system is used to demonstrate the effectiveness of the proposed
Keywords: Congestion Management, Demand Response, Interruptible Load.
Modeling and Evaluating of Protection Schemes based on Petri Nets
Vol. 4. n. 1, pp. 180-187
Abstract - In this
paper, Petri nets have been used for modeling and evaluating of
protection schemes of electric power system. By this approach, the
processing time of information is reduced and the accuracy of fault
detection procedure is increased. Simulation results show that Petri
nets make possible the statistical analyzing and evaluation of
protection systems operation.
Keywords: Petri Nets, Modeling, Protection System, Monitoring, Uncertainty.
Microgrids Control in Islanding Mode Operation considering a Hybrid Model of
Distributed Generation Units of Wind and Fuel Cell
Vol. 4. n. 1, pp. 188-195
Abstract - This
paper presents the control of microgrids electrical parameters of
voltage and frequency in islanding mode of operation in a hybrid model
of distributed generation units of wind and fuel cell.
Keywords: Microgrid, Distributed Generation, Islanding Mode Operation, Power Electronic Converters, Voltage And Frequency Control.
Development of BSDC Index Application for Analysis of Voltage Instability in the
Presence of Voltage Dependent Loads
Vol. 4. n. 1, pp. 196-201
Abstract - In this
paper, an algorithm for diagnosis of voltage collapse point is proposed.
The algorithm is based on load characteristics, voltage and current
measurements. When all loads at a bus are voltage independent type, the
voltage collapse point coincides with Maximum Loading Point. In maximum
loading point, with voltage and current changes, apparent power
delivered to the bus does not increase. In these conditions, BSDC index
that is based on the apparent power difference at the bus equals 0 in
the voltage collapse point.
Keywords: Voltage Collapse, Bus S Difference Criterion, Voltage Instability, Local Measurement.
A Hybrid Solution using Distributed Passive Filters and UPQC to Improve Power
Quality in Dispersed Generation Systems
Vol. 4. n. 1, pp. 202-206
Abstract - This
paper presents a hybrid power quality solution in a test system
consisting of distributed passive filters, an Universal Power Quality
Conditioner (UPQC) and Distributed Generation (DG) units. In the system,
single passive filters are designed and connected to eliminate main
harmonics and compensate reactive power for each nonlinear load. The
UPQC is utilized for voltage unbalance compensation and cancellation of
the remaining current harmonics at the point of common coupling of the
power distribution system. Configuration of the test system, nonlinear
loads, DGs, active filters and UPQC and their modeling in Matlab
software are presented in this paper. Matlab implementation of the
control system based on dq reference frame theory is also described.
Frequency response of the given system is performed and presented to
study the issue of resonance under harmonic conditions. Simulation
results are demonstrated and confirmed the effectiveness of the proposed
configuration in simulated test system. It is shown that the UPQC rating
can be reduced in the proposed configuration due to the reactive power
compensation using passive filters.
Keywords: Passive Filters, UPQC, DG, Load Unbalance, Power Quality.
Arcing Fault Detection for a Double Busbar Metal Enclosed Switchgear
Vol. 4. n. 1, pp. 207-213
Abstract - Arcing
fault issues have increased concern and awareness of many people in
different background. The effect it causes leads to the development of
arc fault detectors. Arc fault detector is associated with overcurrent
relay in older switchgear system to improve speed performance of
switchgear protection system. In this paper, a new design of arc fault
detector for double busbar metal-enclosed medium voltage switchgear is
introduced to develop a better arc fault detection in terms of
selectivity. A position sensor is associated concurrently with light and
current detector in providing a tripping signal to the corresponding
circuit breaker. The circuit is designed using Boolean algebra
approached and simulated in MATLAB Simulink. Simulation results are
observed to verify the performance of the arc fault detector in terms of
solving false tripping problems.
Keywords: Arc Protection, Double Busbar Switchgear.
DG Allocation Using Clonal Selection Algorithm (CSA) to Minimize Losses and
Improve Voltage Security
Vol. 4. n. 1, pp. 214-219
Abstract - The
purpose of this paper is to minimize losses and improving voltage
security by DG allocation based on Clonal Selection Algorithm (CSA).The
exigency for flexible electric system, Energy saving, Loss minimizing
and environmental effects are providing motivation to the development of
distributed generation. These days Scientists research shows that 30% of
Generation of electrical energy is distributed. This subject caused to
perform more studies about DG. It is obvious that losses are in any
network, but DG be able to minimize the losses. The allocation of DG has
the main effect of voltage improve and loss minimizing on the system.
Finally the results are compared to Genetic Algorithm.
Keywords: Distributed Generation, Voltage Security, DG Allocation, Clonal Selection Algorithm, Genetic Algorithm.
Dual Functional UPQC to Improve Power Quality and Injection of Photovoltaic
Array Power to Grid
Vol. 4. n. 1, pp. 220-227
Abstract - In this
paper the design of combined operation of UPQC and PV array is proposed.
The proposed system is composed of series and shunt inverters, PV array
connected to DC link by boost converter which is able to compensate the
voltage sag and swell and voltage interruption, harmonics and reactive
power in both islanding and interconnected modes. The proposed system is
able to inject the active power to grid in addition to its ability in
improvement of power quality in point of common coupling. Also it can
provide a part of sensitive load power during voltage interruption. The
results of simulation in MATLAB/SIMULINK software show that the
mentioned system operates correctly.
Keywords: Unified power quality conditioner (UPQC), Photovoltaic array (PV), Interconnected mode, Islanding mode, Maximum power point tracking (MPPT).
The Effect of Solid State Fault Current Limiter in Distribution Grid with
Vol. 4. n. 1, pp. 228-235
Distributed generation (DG) is predicted to play an increasing role in
the electric power system of the near future. DGs are being introduced
to power systems to secure the electric power supply. However, expose of
DG, can alter the fault current during a grid disturbance and disturb
the existing distribution protection system. After connecting DG, part
of the system may no longer be radial, which means the coordination
might not be hold. This will give rise to fault current which is
normally greater than interrupt capability of reclosers and fuses. The
degree of the problem tends to increase when several DG sources are
installed in the system. The introduction of Solid State Fault Current
Limiters (SSFCLs) becomes an effective way for suppressing such a high
short-circuit current fault in distribution systems. In this paper a
solid state fault current limiter (SSFCL) application is proposed to
minimize the effect of the DG on the distribution protection system in a
radial system during a fault. Simulation is accomplished in PSCAD/EMTDC.
Keywords: Solid State Fault Current Limiter, Distribution System, Distributed Generation, Recloser-Fuse Coordination.
Inter-Phase Power Controllers Application to Reduce Transmission Network Short
Circuit Level: System Planning and Engineering Considerations
Vol. 4. n. 1, pp. 236-240
Abstract - In the
steady state condition, an IPC controls power flow by setting PST phase
angle. In this paper, an efficient algorithm is presented to specify
location and the IPC parameters as a fault current limiter including
angels of phase shifting transformer (PST) and reactances of the reactor
and the capacitor. As a case study, the algorithm is applied to Tehran
Regional Electric Company (TREC) to reduce the Short Circuit Level (SCL)
of critical transmission substations. The transient stability studies
are performed in the transmission network with the installed IPC to
verify the effective current limiting characteristic of IPC.
Keywords: IPC, Fault Current Limiting, Transient Stability.
A New Control Strategy for Achieving Minimum Power Injection of Dynamic Voltage
Vol. 4. n. 1, pp. 241-248
Abstract - This
paper presents a new DVR design and a control mechanism to minimize
active power injection and forced the load voltage to be in phase with
grid voltage during the sag, swell and short outage for the non linear
load. The control technique incorporates a short time delay and
mitigates the harmonic distortion during the charging of the energy
storage capacitor. The new design is based on two continuous vector
control. It extracts the fundamental components of the measured voltage
and current using a 12 switch inverter connected in parallel to improve
the time response. The proposed control method is tested on an 11 kV
distribution system. Photovoltaic source with a boost converter is
included to support the DC source during voltage sag. It shows that the
proposed method improve the in-phase compensation technique, minimum
active power and response for nonlinear loads.
Keywords: Two Continuous Vector Control, Dynamic Voltage restorer, Voltage Sag.
A Fast Computational Technique to Trace V – Q Curve Using Broyden – Shamanski
Vol. 4. n. 1, pp. 249-254
Abstract - The V – Q
curve analysis has been widely used for voltage stability studies by
many power system utilities over the past years. The power flow
technique used to trace V – Q curve is conventional Newton Raphson (NR)
method. Though NR method is accurate, it needs high computational time
due to the presence of repeated Jacobian inverses. This paper
investigates a novel approach to solve power flow using Broyden –
Shamanski method with Sherman – Morrison formula (BSS) to trace V – Q
curve which eliminates the drawback of NR method without compromising
accuracy. Simulation test is carried on IEEE 14, 30, 57 and 118 bus test
systems using NR and BSS method. Results indicate that the computational
time for tracing V – Q curve using the proposed BSS method is far less
when compared to that of conventional NR method.
Keywords: Broyden – Shamanski, Newton Raphson, Power Flow, V – Q curve, Voltage Stability.
International Review on Modelling and Simulations - Papers (Part B)
On Some Numerical Methods for the Non Linear Transport Equation in 3D
Vol. 4. n. 1, pp. 255-261
Abstract - In this
paper the simulation of the phenomenon of homogeneous and isotropic
turbulent flow in free-surface channels is studied in 3D.The method of
finite volumes is used to solve the non linear transport equations
(convection-diffusion problem) which are equations of quantity of
motion, kinetic energy, dissipation, and tracking the volume fraction of
each fluid in the whole filed. Numerical results are obtained by two
models, the multiphasic model V.O.F (Volume of Fluid) and the model for
Keywords: Numerical Simulation, Finite Volume, Nonlinear Transport Equation, VOF Model.
Multi-Scale Multi-Physics Modeling of Bundled Multiwalled Carbon Nanotube
Vol. 4. n. 1, pp. 262-269
Abstract - CNTs
(Carbon Nanotubes) has exceptional electrical, mechanical, and thermal
properties. Most importantly, both experimental and numerical studies
proved that when CNTs is used as metal or semiconductor material, the
performance of such systems is tremendously improved. This paper aims at
modeling the electrical and magnetic behavior of Bundled Multi-walled
Carbon Nanotubes interconnects for on-chip power delivery among other
applications. Simulation and modeling on the multi-scale and
multi-physics are conducted by performing Extended Finite Element Time
Domain and Extended Finite Difference Time Domain methods analysis in a
hybrid model approach and by utilizing ANSYS®/MAXWELL® 3D software for
the first time. The analysis, modeling, and simulation are used as a
tool to derive the governing relationship of CNTs by considering the
nonlinearity of the mechanism of interfacial bonding with other
materials when subjected to current and voltage excitation. The results
of the model are verified by experimental results from the literature.
Keywords: Carbon Nanotube; Interatomic Potential; Finite Elements; Finite Difference, Modeling; Simulation; Bmwcnt; Mwcnt; Swcnt; Vias; Pillars; Interconnect; Power Delivery.
Electromagnetic Analysis of Railguns by Numerical Simulations
Vol. 4. n. 1, pp. 270-278
Abstract - Nowadays,
the armature transition is one of problems in railguns. Many kinds of
mechanism were proposed by researchers to predict or explain armature
transition phenomena. And many types of railgun were invented. In this
paper, three types of railgun, including simple railgun,
parallel-augmented railgun and muzzle-fed railgun, are investigated with
numerical simulations. Since current density is the decisive factor to
transition velocity, this study focuses on the current distribution in
armature. The inductance gradient of railgun and magnetic field
distribution are also investigated. In order to simplify simulations,
rails and armature are considered in each simulation, and armatures of
railgun are same. The Maxwell 3D modular of Ansoft corp. was utilized as
the program code. The simple railgun is selected as the benchmark, and
the other two types were compared with it. In the simulation of
parallel-augmented railgun, two current sources (500kA, 60Hz) were
connected to inner rails and outer rail independently. In muzzle-fed
railgun simulation, the same current source as in simple railgun was
connected to rails. Based on simulation results, conclusions are drawn
that augmented railgun has the highest inductance gradient and the
largest launcher efficiency. But the current density at rear part of
armature is larger than that of simple railgun if the currents flowing
through inner rails and outer rail are equal. The inductance gradient of
muzzle-fed railgun is the smallest, but the current density at armature
shoulder is the largest. Projectiles of muzzle-fed railgun will face the
greatest magnetic flux density.
Keywords: Inductance Gradient, Muzzle-Fed, Parallel-Augmented, Projectile, Railgun.
Discrete Wavelet Decomposition Applied to Position Sensor Default Detection on a
PMSM Traction Drive
Vol. 4. n. 1, pp. 279-286
Abstract - This
paper focuses on position sensor default detection on a Permanent Magnet
Synchronous Motor (PMSM) traction drive. The proposed detection method
consists in using Discrete Wavelet Transform technique (DWT), based on
Multiresolution Analysis (MRA). The default considered is a position
sensor disturbance induced by a high level external noise. The
disturbance effects on the traction drive operation are studied. The
multiresolution analysis is applied to stator current signals to detect
the disturbance which affects the measured position. Simulation results
prove the effective detection of the disturbance occurrence using DWT
Keywords: PMSM, Position Sensor, Disturbance, Detection, Multiresolution Analysis.
Multiobjective Optimal Design of Transformer using Bacterial Foraging Algorithm
Vol. 4. n. 1, pp. 287-294
Transformer is a static electromagnetic device that transfers electrical
energy from one level to another by magnetic coupling. This serves very
important link between the electrical energy generation and its
utilization. The optimal design emphasizes for the effective performance
of transformer. The transformer design involves a number of parameters
that makes the problem more complex and non linear and the efficient
methods are need for the optimal design. The optimal design is not only
involve the minimization of cost but also the maximization of
performance or efficiency. In this paper a Multi Objective Bacterial
Foraging Algorithm (MOBFA) has been developed for the optimal design of
transformers. The effectiveness of the proposed method is tested with
the suitable sample transformers and the simulation results are compared
with the recent reports. Numerical results indicate that the proposed
MOBFA outperforms the existing methods in terms of solution quality.
Keywords: Transformer Design, Cost, Efficiency, Multi Objective Optimization, Bacterial Foraging Algorithm.
Transient-State Modeling of Distribution Transformers
Vol. 4. n. 1, pp. 295-302
Abstract - In this
paper, a black box model is proposed to analyze the transient state of
distribution transformers. This model is capable of showing the
frequency characteristics of the transformer under various conditions of
the terminals connections up to the frequency domain of almost 1.2 MHz.
In addition, this model has satisfactory abilities in illustrating the
characteristic of the wave transferred to the consumer side and it can
be employed in studying the over voltages produced in the transformers
terminals as the result of striking the lightning waves. In order to
investigate the validity as well as the accuracy of the proposed model,
a 6300/420 V, 2500 KVA distribution transformer is selected for the
research. First, required experiments are performed on this transformer
and then, using the measurements results and applying the modal
analysis, the model parameters are obtained. Comparing the results of
the model and the measurements findings shows that the proposed model
can be utilized for transient studies in distribution networks.
Keywords: Distribution Transformer, Transient State, Black Box model, Modal Analysis.
Vol. 4. n. 1, pp. 303-309
Abstract - One of
applications of double sided linear induction motor is for investigating
about aerodynamic conditions of aircraft and submarine hydrodynamic
conditions, instead of real size model, models with smaller size can be
moved with appropriate speed by linear induction motor above the water
surface or inside of the water channel test. As a special and distinct
feature, the linear induction motor generates attractive force between
the primary and secondary members in addition to the propulsive force,
which brake the motion during accelerating as well as imposes the
control problem owing to the coupled flux and motion dynamics with the
advantage of reducing the possibility of derailment. In this paper, the
flux and motion dynamics for independent control of attraction and
propulsion force is decoupled. This control strategy allows high
performance to be achieved from linear induction motor.
Keywords: Independent Control, Attractive Force, Linear Motors, Motion Dynamics.
Parameter Estimation of Three Phase Transformer based on Bacterial Foraging
Vol. 4. n. 1, pp. 310-317
Abstract - Due to
the importance of transformers to power systems, investments in studies
are justified in order to develop mathematical models to better
understand equipment characteristics. The methodology used in this study
consisted of the traditional open and short-circuit tests (OC and SC
tests) of the three phase transformer to estimate the equivalent circuit
parameters based on Bacterial Foraging Algorithm (BFA).The performance
characteristics, such as efficiency and voltage regulation are
considered along with the name plate data in order to minimize the error
between the estimated and measured data. The estimation procedure is
demonstrated with a sample three phase transformer and the results are
compared against the conventional method. Results of experiments show
that the proposed method to accelerate the convergence of the estimation
and improve the accuracy of the parameters.
Keywords: Three Phase Transformer, Parameter Estimation, Bacterial Foraging Algorithm.
Application of D-STATCOM to Improve the Power Quality and Transient Operation of
Vol. 4. n. 1, pp. 318-324
Abstract - This
paper discusses the operation of a distribution static compensator (D-STATCOM)
based on three leg voltage source converter (VSC) in three. Phase four
wire distribution systems. This device causes power quality improvement
under unbalanced load, and regulates voltage when an induction Motor in
system starts up.
Keywords: D-STATCOM, Power Quality Improvement, Voltage Source Converter (VSC), Induction Motor, Active Filter.
Models and Simulations for Reconfigurable Magnetic-Coupling Thrusters Technology
Vol. 4. n. 1, pp. 325-334
Abstract - This
paper describes the theory and experiments of a new technology for
re-orienting propellers of underwater thrusters and thus, vectoring AUV
thrust. The principle is to extend the potentialities of
magnetic-coupling motor shafts by adding degrees of freedom in their
kinematics. The idea is to redirect the propeller and therefore, the
thrust vector to a desired direction without moving the whole thruster
body. The focus of this work is to understand how does behave the
magnetically transmitted coupling torque with regard to the new
kinematics of the propeller shaft. After justifying the concept,
reviewing existing AUV locomotion systems, we introduce the theory
underlying this thruster technology and bring numerical simulations for
two design examples. Some experimental results are given for a
laboratory set up, then for an existing and reconfigured thruster that
confirm the insights brought by the theory. The feasibility of this
technique is then discussed based on potential integration and
developments on real AUVs. The conclusion marks these results as an
interesting step to achieve full 3D smooth control of agile AUVs in near
Keywords: AUV Vectorial Thrust, Magnetic-Coupling, Modelling, Simulation, Experiments.
Vol. 4. n. 1, pp. 335-341
Abstract - The
finite element variational formulation of the impedance boundary
condition (IBC) is developed and applied to solve two-dimensional eddy
current problems, especially at high frequencies in electrical machines.
This formulation is used to compute the ac resistance and the self
inductance per unit length of a reverse ‘T’ slot-embedded conductor and
a simple slot-embedded conductor. The proposed IBC formulation is very
efficient, because it does not change the sparsity of the finite element
global matrix as well as it has minimized the computing cost such as
computer memory and central processing unit time. The obtained results
of both the finite element method (FEM) and the developed IBC
formulation are compared to published results.
Keywords: Eddy Currents, FE-Formulation, IBC Formulation, Slot-Embedded Conductor.
Modeling and Comparison of Traction Transformers based on the Utilization Factor
Vol. 4. n. 1, pp. 342-351
Abstract - Electric
railways inject undesirable harmonics and large negative sequence
component to the utility grid due to their essential characteristics
(i.e. non-linear, non-sinusoidal, non-symmetrical, and non-continuity).
Traction transformers with a special connection (i.e. Single-phase, V/V,
Wye-Delta, Scott, and Le-Blanc) are one of the best solutions to limit
the above drawbacks and also improve the efficiency and power factor of
the utility grid. They have been selected on the basis of electrical
performance, physical profile of the network, and economics issues.
Traction load variation, negative sequence component, load harmonic
currents, power factor, and efficiency as effective electrical
parameters were investigated for aforementioned traction transformers.
However, there are other influential and important parameters in the
electrical railway systems which are not considered in the research
works. Therefore, this paper defines these factors (utilization factors
of the traction transformer and transmission line) as mathematical
equations and then investigates the impacts of harmonic components and
unbalance loading on these factors.
Keywords: Traction Transformer, Unbalance Loading, Line Utilization Factor, Transformer Utilization Factor.
Analysis of UPQC with Super-Capacitor to Power Quality Enhancement and Energy
Vol. 4. n. 1, pp. 352-357
Abstract - This
paper proposes a new configuration of UPQC (Unified Power Quality
Conditioner) that consists of the DC/DC converter and the
super-capacitors for compensating the voltage interruption. The proposed
UPQC can compensate the reactive power, harmonic current, voltage sag
and swell, voltage unbalance, and the voltage interruption. The
performance of proposed system was analyzed through simulations with
MATLAB\SIMULINK software. The proposed system can improve the power
quality at the common connection point of the non-linear load and the
Keywords: Unified Power Quality Conditioner (UPQC), Voltage Interruption, DC/DC Converter, Super-Capacitor.
Modeling and Simulation of Centrifugal Gas Compressor Using Adaptive Neuro-Fuzzy
Inference System: Application to the Modeling and Simulation of the Industrial
Vol. 4. n. 1, pp. 358-363
Abstract - In this
paper, the modeling and simulation of a centrifugal gas compressor based
on adaptive neuro-fuzzy inference system (ANFIS) is presented. A hybrid
learning algorithm consists of back-propagation and least-squares
estimation is used for training. Structures of the ANFIS are developed
and trained in MATLAB 7.0.4 program. This model can reduce the
computational time while keeping the accuracy of physics-based model.
The compact models with ANFIS allow the fast and accurate system level
simulation of the Industrial Packages.
Keywords: Compressor, Artificial Neural Network, Adaptive Neuro-Fuzzy Inference System, Fuzzy System.
Theoretical Investigation on the Thermal Performance of two-Phase Heat Spreaders
including Parallel Microchannels
Vol. 4. n. 1, pp. 364-379
Abstract - A
detailed mathematical model of a two-phase heat spreader with axial
microchannels is developed in which the fluid flow is considered along
with the heat and mass transfer processes during evaporation and
condensation. The model is based on the equations for the mass, momentum
and energy conservation, which are written for the evaporator,
adiabatic, and condenser zones. The model, which permits to simulate
several shapes of microchannels, can predict the maximum heat transfer
capacity of the two-phase heat spreader, the optimal fluid mass, and the
temperatures and pressure gradients along the microchannel. The effect
of shear stresses at the free liquid surface in a microchannel due to
the frictional liquid-vapor interaction on the liquid flow is taken into
consideration. The heat transfer through the liquid films in both
evaporator and condenser is accounted for in the model, which is
described with respect to the disjoining pressure, interfacial thermal
resistance, surface roughness, and curvature. The thermal resistances of
the evaporator and condenser are determined by accounting for the
longitudinal distribution of the meniscus curvature, which is dependent
on heat load and heat spreader inclination.
Keywords: Electronics Cooling, Mini Heat Pipes, Capillary Structure, Microchannels.
X-FEM Method for Crack Growth Modelling: Concepts and Computer Implementation
Vol. 4. n. 1, pp. 380-387
Abstract - In this
work, we present a method for modeling crack growth without re-meshing
X-FEM. It covers the formulation and implementation of XFEM, and
discusses various aspects of the approach. Concepts of the level set
method and the extended finite element are explained, and there is a
discussion on the enrichment models. It provides a number of simple
instructions and step-by-step procedures for a wide range of engineering
applications. These simple guidelines, in combination with other freely
available XFEM source codes can be used to further advance the existing
XFEM capabilities, and to provide a launching pad for future
improvements and developments. A numerical experiment is provided to
demonstrate the effectiveness and robustness of the XFEM implementation.
Keywords: Singularity, Crack, Fracture, XFEM, LSM, Implementation.
Degenerated Finite Element Modelling: Effect of Size
Vol. 4. n. 1, pp. 388-390
Abstract - On the
basis of fracture mechanics, a numerical study has been considered in
order to study the effect of size of degenerated finite element in
modeling the singularity near the crack tip. It allows to numerically
estimating of the stress intensity factors, for Central Notched
specimen, by using two techniques of modeling (finite element standard
and degenerated finite elements). This work makes it possible to confirm
the aptitude of the degenerated finite elements to model the singularity
accurately existing in the vicinity of the cracks.
Keywords: Degenerated Finite Element, Size, Singularity, Crack, Stress Intensity Factors.
Robust Maximum Power Point Tracking for Fast Changing Environmental Conditions
Vol. 4. n. 1, pp. 391-396
Abstract - In this
paper , we study a system consisting of a photovoltaic (PV) array panel,
dc-to-dc switching converter and a battery. A backstepping PWM
controller is developed to maximize the power of the solar generating
Keywords: Maximum Power Point Tracking, Solar Power Generation, Robust Control, Lyapunov, PWM.
Using H∞ State Estimation for a Cold Flow Circulating Fluidized Bed on Standpipe
Vol. 4. n. 1, pp. 397-403
Circulating fluidized beds (CFB) have been widely applied to many area
of industry such as chemical processing, petroleum refining, catalytic
cracker processing, power generation and waste treatment. The
application of CFBs provides several advantages, such as improving
gas-solid contact, reducing the cross-sectional area because of high
superficial velocities, and having a higher solids flux trough the
reactor. A cold flow circulating fluidized (CFCB) has been built at the
National Energy Technology Laboratory (NETL) in Morgantown recently, a
mathematical model of the CFCFB standpipe was successfully developed and
tested using an extended Kalman filter EKF and an H estimator
algorithm. The H estimator and EKF algorithms have been used to
estimate states such as the void fraction and the bed-height of the
standpipe using pressure drop measurements. Using this standpipe
mathematical model requires a solid circulation rate(SCR) to be a
measurable variable offered from a spiral installed in the standpipe of
CFCFB the spiral device at the standpipe of the NETL CFCFB test bed is
impractical when a CFB system is operating in order to estimate the
solids circulation, using a least squares estimator and a subspace
algorithm. In this model, the measured aeration flow rates and pressure
drop are used as inputs and outputs in the from of a time series in
order to build the state space dynamic model. After this model has been
obtained, the Kalman filter and H algorithms is applied in order to
estimate the solids circulation rate with the measured pressure drop
Keywords: Extended Kalman Filter, H, Cold Flow Circulation Fluidized Bed, Standpipe.
Finite-Element Simulation of Heat Generation by Laser in Welding
Vol. 4. n. 1, pp. 404-408
Abstract - In this
paper, the laser beam welding is studied and aluminum alloy temperature
field is gained in this process. Utilizing laser as a method to join
plastic components is growing in popularity. The ability to create
clean, strong and consistent hermetic seals is very attractive for
Keywords: Aluminum, Laser Beam Welding, Finite-Element, Temperature Field.
Vol. 4. n. 1, pp. 409-416
Abstract - Study of
the vibration of thin cylindrical shells made of a functionally gradient
material (FGM) composed of stainless steel and nickel is very important.
The objective is to study the natural frequencies and the effects
clamped-clamped boundary conditions on the natural frequencies of the
functionally graded cylindrical shell. The study is carried out using
third order shear deformation shell theory (T.S.D.T). The analysis is
carried out using Hamilton’s principle. The governing equations of
motion of functionally graded cylindrical shells are derived based on
T.S.D.T theory. Results are presented on the frequencies characteristics
and the effects of clamped-clamped boundary conditions on edge end
functionally graded cylindrical shell.
Keywords: Vibration, Cylindrical Shell, Hamilton’s Principle.
Shape and Dimension Estimation of Cracks using Neural Network in Eddy Current
Vol. 4. n. 1, pp. 417-421
Abstract - This
paper proposes a method for the reliable estimation of crack shape and
dimensions in conductive materials using a suitable nondestructive
instrument based on the eddy current testing principle and machine
learning system postprocessing. The artificial neural network estimates
shape and dimension of new cracks using impedance changes of eddy
current probe. The experimental results and finite element method is
used for training the artificial neural network and the simulation
results are very promising. By increasing the numbers of experiments,
finite element method is not necessary.
Keywords: Nondestructive Testing; Eddy Current; Artificial Neural Network; Finite Element Method; Feed Forward Backpropagation.
Estimation of Location and Magnitude of Harmonic Sources by Optimal Measurement
Vol. 4. n. 1, pp. 422-428
Abstract - In this
research, a new method is proposed to solve the problem of optimal
placement of meters for static estimation of harmonic sources in a power
system. Because of limitation the number of harmonic measurements that
must be installed in the network, harmonic state estimation has been
considered as one of the famous methods for measuring voltage and
injection current busbar, lines current and placement these measurements
with algorithm based on sequential elimination method. Also, after that
algorithm could find location of measurements in various busbars at
harmonics, technique minimization number of sites that they¬ collect
harmonic data from measurement devices, optimal placement of these
measurements will be done. By use this technique, it can find optimal
place of measurement for identification location and intensity of
harmonic sources. This investigation have been performed on IEEE 14-bus
with 69 possible location to install these measurement in Matlab
Keywords: Harmonic Measurement, Modeling, Optimal Placement, Condition Number.
Airflow Simulation of Particle Suction in Hard Disk Drives Manufacturing Process
Vol. 4. n. 1, pp. 429-435
Abstract - In Hard
Disk Drive (HDD), particles are the major problem during the operation
of HDD. Thus, in the HDD manufacturing process, particles are one of the
important controlled parameters. In some processes particles are removed
from the HDD using suction tools. The designs of these tools affect the
efficiency of particle removing process. Therefore, the prediction of
the airflow induced by the suction tools becomes convenient and useful
for the researchers to develop and improve each component of the tools
and also the production. This project is to analyze the particle
productivity and aim to improve it. In order to do so, the airflow
simulation is needed to be done. The airflow is modeled and simulated
using ANSYS CFX software. The suction tool is simulated at various
operating height; 1 mm, 2 mm, 5 mm, and 10 mm. From the results, it is
seen that the operating height of the suction tool affects the flow
characteristic of the particle. The best operating height is 5 mm. This
will lead the researchers and engineers to understand about the effect
of each component and design of the suction tools to airflow and
Keywords: Airflow, Hard Disk Drive, Particle, Simulation, Suction Tools.
Temporal Neuro-Fuzzy Systems in Fault Diagnosis and Prognosis
Vol. 4. n. 1, pp. 436-440
Abstract - Fault
diagnosis and failure prognosis are essential techniques in improving
the safety of many manufacturing systems. Therefore, on-line fault
detection and isolation is one of the most important tasks in
safety-critical and intelligent control systems.
Keywords: Diagnosis; Artificial Neuronal Networks; Fuzzy Logic; Neuro-Fuzzy Systems; Pattern Recognition; FMEAC.
A Hybrid State Space Model for Single Stage Three-Level Resonant Rectifiers
Vol. 4. n. 1, pp. 441-456
Abstract - This
paper presents a state space model based on a combined averaging and
multiple frequency models suitable for the prediction of the performance
of a single stage three level resonant AC/DC converter operated with
variable frequency asymmetrical pulse width modulation control or
variable frequency phase shift modulation control to regulate the output
voltage, shape the input current as well as to control the dc bus
voltage. The pulse width modulation/phase shift modulation aims to
regulate the input current shape as well as the level of the dc-bus
voltage; whereas, the variable frequency provides a tightly regulated
output voltage. This model is obtained by first deriving an average
model of the switching converter, which is then analyzed to its
frequency components. This results in substituting fast and slow
oscillating values at steady state with variables that have a dc steady
state value. This modeling approach is generally useful for variable
frequency application and can be used at a detailed level that includes
effect of parasitics, to a simplified linearized or a decoupled model to
get steady state estimates of performance. The proposed model gives very
good performance prediction under transient and steady state conditions
and facilitates a better controller design.
Keywords: Power Factor Correction, Multiple Frequency Averaging, State Space Model.
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