This document summarizes a research paper about using nonlinear control of Unified Power Flow Controllers (UPFCs) to damp inter-area oscillations in power systems. The paper proposes a nonlinear control method where UPFCs can control their interface bus angles to mitigate power system oscillations. The control method develops a reduced nonlinear model of the network and uses selected frequency measurements from a subset of dominant machines as inputs to FACTS controllers. The effectiveness of using this method with UPFCs to damp inter-area oscillations is validated on a test power system.
International Journal of Engineering Research and Applications (IJERA) is an open access online peer reviewed international journal that publishes research and review articles in the fields of Computer Science, Neural Networks, Electrical Engineering, Software Engineering, Information Technology, Mechanical Engineering, Chemical Engineering, Plastic Engineering, Food Technology, Textile Engineering, Nano Technology & science, Power Electronics, Electronics & Communication Engineering, Computational mathematics, Image processing, Civil Engineering, Structural Engineering, Environmental Engineering, VLSI Testing & Low Power VLSI Design etc.
Efficacy of Facts in Power Oscillation Damping and Renewable IntegrationIOSRJEEE
This paper discusses about the approach towards effective power oscillation damping, root causes for the genesis of power oscillation and various methodologies adopted to eradicate it.This paper presents an unified approach of FACTS controller installation in order to ensure effective power oscillation damping. The power oscillations, if not controlled within time, may aggravate the entire power system’s functioning and ultimate outcome as blackout. The network congestion has been a matter of serious concern to utility operations due to classical transmission corridors and inadequate controllers’ deployment. The necessity of system regulations demands an adequate controller for matching the power requirement variability and this has been demonstrated with STATCOM control feature. This controller enhances the Available Transfer Capability along with security and reliability. IEEE 14 Bus system is simulated and studied with various scenarios with the help of MATLAB and PSAT to identify various complexities and to resolve these issues so as to enhance the ATC, reliability and security
FLC based on static var compensator for power system transient stability enha...TELKOMNIKA JOURNAL
Transient Stability is the capability of a system to be able to return to its normal state after experiencing large disturbances. The static var compensator (SVC) is a shunt device of the flexible AC transmission systems (FACTS) family using power electronics to improve transient stability in power system. For the SVC control, it is usually used a PI controller, although PI controller is simpler and cheaper but not suitable when power system is subjected to transient stability since power system become non-linear system. In order to overcome this problem, the PI controller combined with Fuzzy controller is designed. Two types of faults were considered for this study to examine the effect of the fuzzy-SVC controller on system transient stability, the proposed fault types are single line to ground fault and three lines to ground fault. The performance and behavior of the designed fuzzy controller compared with that of the conventional PI controller in term of terminal voltage, rotor angle, and transmission line active power.
International Journal of Engineering Research and Applications (IJERA) is an open access online peer reviewed international journal that publishes research and review articles in the fields of Computer Science, Neural Networks, Electrical Engineering, Software Engineering, Information Technology, Mechanical Engineering, Chemical Engineering, Plastic Engineering, Food Technology, Textile Engineering, Nano Technology & science, Power Electronics, Electronics & Communication Engineering, Computational mathematics, Image processing, Civil Engineering, Structural Engineering, Environmental Engineering, VLSI Testing & Low Power VLSI Design etc.
Efficacy of Facts in Power Oscillation Damping and Renewable IntegrationIOSRJEEE
This paper discusses about the approach towards effective power oscillation damping, root causes for the genesis of power oscillation and various methodologies adopted to eradicate it.This paper presents an unified approach of FACTS controller installation in order to ensure effective power oscillation damping. The power oscillations, if not controlled within time, may aggravate the entire power system’s functioning and ultimate outcome as blackout. The network congestion has been a matter of serious concern to utility operations due to classical transmission corridors and inadequate controllers’ deployment. The necessity of system regulations demands an adequate controller for matching the power requirement variability and this has been demonstrated with STATCOM control feature. This controller enhances the Available Transfer Capability along with security and reliability. IEEE 14 Bus system is simulated and studied with various scenarios with the help of MATLAB and PSAT to identify various complexities and to resolve these issues so as to enhance the ATC, reliability and security
FLC based on static var compensator for power system transient stability enha...TELKOMNIKA JOURNAL
Transient Stability is the capability of a system to be able to return to its normal state after experiencing large disturbances. The static var compensator (SVC) is a shunt device of the flexible AC transmission systems (FACTS) family using power electronics to improve transient stability in power system. For the SVC control, it is usually used a PI controller, although PI controller is simpler and cheaper but not suitable when power system is subjected to transient stability since power system become non-linear system. In order to overcome this problem, the PI controller combined with Fuzzy controller is designed. Two types of faults were considered for this study to examine the effect of the fuzzy-SVC controller on system transient stability, the proposed fault types are single line to ground fault and three lines to ground fault. The performance and behavior of the designed fuzzy controller compared with that of the conventional PI controller in term of terminal voltage, rotor angle, and transmission line active power.
VFT Application for Asynchronous Power TransferIDES Editor
The variable frequency transformer (VFT) developed
recently is a flexible asynchronous ac link which is used to
transfer power in-between asynchronous power system
networks. The first VFT was installed at the Langlois
substation, which interconnects the New York (USA) and the
Hydro-Québec (Canada) systems. Basically, it is a rotary
transformer whose torque is externally adjusted in order to
control the power transfer. In the paper, a simulated model of
VFT is present, which is used as a controllable bidirectional
power transmission device that can control power transfer
through the asynchronous power system networks. A digital
simulation model of VFT and its control system are developed
with MATLAB Simulink and a series of studies on power
transfer through asynchronous power system networks are
carried out with this model. Moreover, the response
characteristics of power transfer under various torque
conditions are discussed. Further voltage, current, torque and
power transfer plots are also obtained. Thus, the VFT concept
and its advantages are verified by simulation results.
Performance improvement of parallel active power filters using droop control ...Ghazal Falahi
In this paper, a new method based on droop control scheme is proposed for controlling parallel operation of active filters. The harmonic components of the load current are extracted by an enhanced phase-locked loop (EPLL). In the parallel group, each filter operates as a conductance and the harmonic workload is shared among them. A droop relationship between the conductance and non-fundamental apparent power controls the operation of each unit. The non-fundamental apparent power has been calculated based on IEEE Std 1459. Principles of operation are explained in this paper and simulation results which are presented approve the effectiveness of this method. The results indicate a significant reduction in Total Harmonic Distortion (THD) in a rectifier application.
International Journal of Engineering Research and Applications (IJERA) is an open access online peer reviewed international journal that publishes research and review articles in the fields of Computer Science, Neural Networks, Electrical Engineering, Software Engineering, Information Technology, Mechanical Engineering, Chemical Engineering, Plastic Engineering, Food Technology, Textile Engineering, Nano Technology & science, Power Electronics, Electronics & Communication Engineering, Computational mathematics, Image processing, Civil Engineering, Structural Engineering, Environmental Engineering, VLSI Testing & Low Power VLSI Design etc.
Comparison of Dynamic Stability Response of A SMIB with PI and Fuzzy Controll...ijeei-iaes
Consumer utilities are non –linear in nature. This injects increased flow of current and reduced voltage with distortions which cause adverse effect on the stability of consumer utilities. To overcome this problem we are using a modern Flexible Alternating Current Transmission System controller i.e. distributed power flow controller (DPFC). This controller is similar to UPFC, which can be installed in a transmission line between the two electrical areas. In DPFC, instead of the common Dc link capacitor three single phase converters are used. In this paper we are concentrating on system stability (oscillation damping). For analyzing the stability of a single machine infinite bus system (SMIB) we have used PI controlled Distributed Power Flow Controller (DPFC) and Fuzzy controlled DPFC. All these models are simulated using MATLAB/SIMULINK. Simulation results shows Fuzzy controlled DPFC are better than PI controlled DPFC. The significance of the results are better stability and constant power supply.
Enhanced Torque Control and Reduced Switching Frequency in Direct Torque Cont...IJPEDS-IAES
Direct Torque Control (DTC) of induction machine has received wide
acceptance in many adjustable speed drive applications due to its simplicity
and high performance torque control. However, the DTC using a common
two-level inverter poses two major problems such as higher switching
frequency (or power loss) and larger torque ripple. These problems are due to
inappropriate voltage vectors which are selected among a limited number of
voltage vectors available in two-level inverter. The proposed research aims to
formulate an optimal switching strategy using Dual-Inverter Supplied Drive
for high performances of DTC. By using dual-inverter supplied, it provides
greater number of voltage vectors which can offer more options to select the
most appropriate voltage vectors. The most appropriate voltage vectors
should able to produce minimum torque slope but sufficient to satisfy torque
demands. The identification is accomplished by using an equation of rate of
change of torque which is derived from the induction machine equations. The
proposed strategy also introduces a block of modification of torque error
status which is responsible to modify the status such that it can determine the
most optimal voltage vectors from a look-up table, according to motor
operating conditions. The improvements obtained are as follows; 1)
minimization of switching frequency (reduce power loss), and 2) reduction of
torque ripple. Some improvements obtained in the proposed strategy were
verified via experimentations.
Comparison of Multi-Machine Transient Stability Limit Using UPFCIJMTST Journal
The stability of an interconnected power system is compare to normal or stable operation after having been
subjected to some form of disturbance. With interconnected systems continually growing in size and extending
over vast geographical regions, it is becoming increasingly more difficult to maintain synchronism between
various parts of the power system. This paper investigates the comparison of transient stabil ity limit of a
multi-machine power system wi th the help of a UPFC operated in perpendicular vol tage control
mo d e an d t h e i r i t ’ s c omp ar i s o n .
Proposed Method for Shoot-Through in Three Phase ZSI and Comparison of Differ...IAES-IJPEDS
This paper presented the new methodology for different control techniques applied to three phase Z-source inverter for minimisation of switching losses. The procedure for proposed control techniques and its effects on the performance of operation of three phase Z-source inverter are analyzed. The graphs for voltage gain and voltage stress are drawn for different control methods. The flow-chart for the symmetrical and unsymmetrical control techniques for creating pulse signals for switches of three phase inverter are shown. All the methods are studied and compared with each other. The Total harmonic distortion (THD) of output voltage of both the control methods has been analyzed using FFT analysis. The experiments done and the results shown for capacitor voltage, load current and load line voltage for simple boost and constant boost control techniques are presented using MATLAB/ Simulink.
The use of conventional devices as control mechanism for system voltage profile enhancement
and loss reduction is still predominantly prevalent in most third world nations and Nigeria is never an
exemption. This study seeks to compare efficiency of Load Tap-Changing Transformer and Shunt Capacitors
using system voltage profile enhancement and real power loss minimization as performance matrix on
Nigerian 330kV, 24-Bus grid system as a test case. In this work, the Newton Raphson iterative algorithm was
adopted due to its superior features over other iterative techniques. Load flow analysis was performed on the
test case with and without incorporation of LTCT and Shunt Capacitors, the result of the analysis shows that
with shunt capacitors injection at the weak buses identified, the algorithm converged in 5 iterations but with
LTC transformer convergence was achieved in 4 iterations. Also, the total system losses with shunt capacitor
injection was found to be 82.2826MW which is about 4.1% reduction while with LTC transformer, the total
system losses reduced appreciably to 81.9865MW which is about 4.8% reduction. Incorporation of LTCT
gives a better improvement on system voltage profile compared with the improvement observed with shunt
capacitor injection at the defective buses identified.
Modeling, Analysis and Simulation of VFT for Power Flow Control through Async...IDES Editor
Variable Frequency Transformer (VFT) is a
controllable bi-directional transmission device that can
transfer power between asynchronous networks. It avoids both
HVDC link and FACTS based power transmission control
system. Basically, it is a rotatory transformer whose torque is
adjusted in order to control the power flow. In this paper, a
simulated model of VFT is used as a controllable bidirectional
power transmission device that can control power flow through
the connected asynchronous power systems. A simulation
model of VFT and its control system models are developed
with MATLAB and a series of studies on power flow through
asynchronous power systems are carried out with the model.
The response characteristics of power flow under various
torque conditions are discussed. The voltage, current, torque
and power flow plots are also obtained.
International Journal of Computational Engineering Research(IJCER)ijceronline
International Journal of Computational Engineering Research(IJCER) is an intentional online Journal in English monthly publishing journal. This Journal publish original research work that contributes significantly to further the scientific knowledge in engineering and Technology.
International Journal of Engineering Research and Applications (IJERA) is an open access online peer reviewed international journal that publishes research and review articles in the fields of Computer Science, Neural Networks, Electrical Engineering, Software Engineering, Information Technology, Mechanical Engineering, Chemical Engineering, Plastic Engineering, Food Technology, Textile Engineering, Nano Technology & science, Power Electronics, Electronics & Communication Engineering, Computational mathematics, Image processing, Civil Engineering, Structural Engineering, Environmental Engineering, VLSI Testing & Low Power VLSI Design etc.
Low voltage ride through control of modular multilevel converter based hvdc s...Ghazal Falahi
Low Voltage Ride Through (LVRT) is an important grid requirement for Voltage Source Converter (VSC) based HVDC links. This paper studies the performance of the modular multilevel converter (MMC) VSC based HVDC systems during faults or voltage dips and proposes a new control strategy to improve the LVRT performance. The proposed algorithm controls the system to generate the required active and reactive powers that are calculated mathematically based on the ratings of the MMC-HVDC system and LVRT requirements. The injected active and reactive power values obey the LVRT guidelines and are adaptable to different grid codes. The mathematical calculations are presented and EMTDC/PSCAD simulation evaluates the performance of the proposed method.
International Journal of Computational Engineering Research(IJCER) ijceronline
nternational Journal of Computational Engineering Research (IJCER) is dedicated to protecting personal information and will make every reasonable effort to handle collected information appropriately. All information collected, as well as related requests, will be handled as carefully and efficiently as possible in accordance with IJCER standards for integrity and objectivity.
Influence of Skidded Distance on the Initial Velocity of Vehicle in Chain Acc...IJMER
International Journal of Modern Engineering Research (IJMER) is Peer reviewed, online Journal. It serves as an international archival forum of scholarly research related to engineering and science education.
In this paper the finite element analysis of aHeat Exchanger is done. The geometry was
modelled in CATI A V5 R21 and finite element analysis had been performed in ANSYS12 WB. FE analysis
is was used to determine stress analysis at.
VFT Application for Asynchronous Power TransferIDES Editor
The variable frequency transformer (VFT) developed
recently is a flexible asynchronous ac link which is used to
transfer power in-between asynchronous power system
networks. The first VFT was installed at the Langlois
substation, which interconnects the New York (USA) and the
Hydro-Québec (Canada) systems. Basically, it is a rotary
transformer whose torque is externally adjusted in order to
control the power transfer. In the paper, a simulated model of
VFT is present, which is used as a controllable bidirectional
power transmission device that can control power transfer
through the asynchronous power system networks. A digital
simulation model of VFT and its control system are developed
with MATLAB Simulink and a series of studies on power
transfer through asynchronous power system networks are
carried out with this model. Moreover, the response
characteristics of power transfer under various torque
conditions are discussed. Further voltage, current, torque and
power transfer plots are also obtained. Thus, the VFT concept
and its advantages are verified by simulation results.
Performance improvement of parallel active power filters using droop control ...Ghazal Falahi
In this paper, a new method based on droop control scheme is proposed for controlling parallel operation of active filters. The harmonic components of the load current are extracted by an enhanced phase-locked loop (EPLL). In the parallel group, each filter operates as a conductance and the harmonic workload is shared among them. A droop relationship between the conductance and non-fundamental apparent power controls the operation of each unit. The non-fundamental apparent power has been calculated based on IEEE Std 1459. Principles of operation are explained in this paper and simulation results which are presented approve the effectiveness of this method. The results indicate a significant reduction in Total Harmonic Distortion (THD) in a rectifier application.
International Journal of Engineering Research and Applications (IJERA) is an open access online peer reviewed international journal that publishes research and review articles in the fields of Computer Science, Neural Networks, Electrical Engineering, Software Engineering, Information Technology, Mechanical Engineering, Chemical Engineering, Plastic Engineering, Food Technology, Textile Engineering, Nano Technology & science, Power Electronics, Electronics & Communication Engineering, Computational mathematics, Image processing, Civil Engineering, Structural Engineering, Environmental Engineering, VLSI Testing & Low Power VLSI Design etc.
Comparison of Dynamic Stability Response of A SMIB with PI and Fuzzy Controll...ijeei-iaes
Consumer utilities are non –linear in nature. This injects increased flow of current and reduced voltage with distortions which cause adverse effect on the stability of consumer utilities. To overcome this problem we are using a modern Flexible Alternating Current Transmission System controller i.e. distributed power flow controller (DPFC). This controller is similar to UPFC, which can be installed in a transmission line between the two electrical areas. In DPFC, instead of the common Dc link capacitor three single phase converters are used. In this paper we are concentrating on system stability (oscillation damping). For analyzing the stability of a single machine infinite bus system (SMIB) we have used PI controlled Distributed Power Flow Controller (DPFC) and Fuzzy controlled DPFC. All these models are simulated using MATLAB/SIMULINK. Simulation results shows Fuzzy controlled DPFC are better than PI controlled DPFC. The significance of the results are better stability and constant power supply.
Enhanced Torque Control and Reduced Switching Frequency in Direct Torque Cont...IJPEDS-IAES
Direct Torque Control (DTC) of induction machine has received wide
acceptance in many adjustable speed drive applications due to its simplicity
and high performance torque control. However, the DTC using a common
two-level inverter poses two major problems such as higher switching
frequency (or power loss) and larger torque ripple. These problems are due to
inappropriate voltage vectors which are selected among a limited number of
voltage vectors available in two-level inverter. The proposed research aims to
formulate an optimal switching strategy using Dual-Inverter Supplied Drive
for high performances of DTC. By using dual-inverter supplied, it provides
greater number of voltage vectors which can offer more options to select the
most appropriate voltage vectors. The most appropriate voltage vectors
should able to produce minimum torque slope but sufficient to satisfy torque
demands. The identification is accomplished by using an equation of rate of
change of torque which is derived from the induction machine equations. The
proposed strategy also introduces a block of modification of torque error
status which is responsible to modify the status such that it can determine the
most optimal voltage vectors from a look-up table, according to motor
operating conditions. The improvements obtained are as follows; 1)
minimization of switching frequency (reduce power loss), and 2) reduction of
torque ripple. Some improvements obtained in the proposed strategy were
verified via experimentations.
Comparison of Multi-Machine Transient Stability Limit Using UPFCIJMTST Journal
The stability of an interconnected power system is compare to normal or stable operation after having been
subjected to some form of disturbance. With interconnected systems continually growing in size and extending
over vast geographical regions, it is becoming increasingly more difficult to maintain synchronism between
various parts of the power system. This paper investigates the comparison of transient stabil ity limit of a
multi-machine power system wi th the help of a UPFC operated in perpendicular vol tage control
mo d e an d t h e i r i t ’ s c omp ar i s o n .
Proposed Method for Shoot-Through in Three Phase ZSI and Comparison of Differ...IAES-IJPEDS
This paper presented the new methodology for different control techniques applied to three phase Z-source inverter for minimisation of switching losses. The procedure for proposed control techniques and its effects on the performance of operation of three phase Z-source inverter are analyzed. The graphs for voltage gain and voltage stress are drawn for different control methods. The flow-chart for the symmetrical and unsymmetrical control techniques for creating pulse signals for switches of three phase inverter are shown. All the methods are studied and compared with each other. The Total harmonic distortion (THD) of output voltage of both the control methods has been analyzed using FFT analysis. The experiments done and the results shown for capacitor voltage, load current and load line voltage for simple boost and constant boost control techniques are presented using MATLAB/ Simulink.
The use of conventional devices as control mechanism for system voltage profile enhancement
and loss reduction is still predominantly prevalent in most third world nations and Nigeria is never an
exemption. This study seeks to compare efficiency of Load Tap-Changing Transformer and Shunt Capacitors
using system voltage profile enhancement and real power loss minimization as performance matrix on
Nigerian 330kV, 24-Bus grid system as a test case. In this work, the Newton Raphson iterative algorithm was
adopted due to its superior features over other iterative techniques. Load flow analysis was performed on the
test case with and without incorporation of LTCT and Shunt Capacitors, the result of the analysis shows that
with shunt capacitors injection at the weak buses identified, the algorithm converged in 5 iterations but with
LTC transformer convergence was achieved in 4 iterations. Also, the total system losses with shunt capacitor
injection was found to be 82.2826MW which is about 4.1% reduction while with LTC transformer, the total
system losses reduced appreciably to 81.9865MW which is about 4.8% reduction. Incorporation of LTCT
gives a better improvement on system voltage profile compared with the improvement observed with shunt
capacitor injection at the defective buses identified.
Modeling, Analysis and Simulation of VFT for Power Flow Control through Async...IDES Editor
Variable Frequency Transformer (VFT) is a
controllable bi-directional transmission device that can
transfer power between asynchronous networks. It avoids both
HVDC link and FACTS based power transmission control
system. Basically, it is a rotatory transformer whose torque is
adjusted in order to control the power flow. In this paper, a
simulated model of VFT is used as a controllable bidirectional
power transmission device that can control power flow through
the connected asynchronous power systems. A simulation
model of VFT and its control system models are developed
with MATLAB and a series of studies on power flow through
asynchronous power systems are carried out with the model.
The response characteristics of power flow under various
torque conditions are discussed. The voltage, current, torque
and power flow plots are also obtained.
International Journal of Computational Engineering Research(IJCER)ijceronline
International Journal of Computational Engineering Research(IJCER) is an intentional online Journal in English monthly publishing journal. This Journal publish original research work that contributes significantly to further the scientific knowledge in engineering and Technology.
International Journal of Engineering Research and Applications (IJERA) is an open access online peer reviewed international journal that publishes research and review articles in the fields of Computer Science, Neural Networks, Electrical Engineering, Software Engineering, Information Technology, Mechanical Engineering, Chemical Engineering, Plastic Engineering, Food Technology, Textile Engineering, Nano Technology & science, Power Electronics, Electronics & Communication Engineering, Computational mathematics, Image processing, Civil Engineering, Structural Engineering, Environmental Engineering, VLSI Testing & Low Power VLSI Design etc.
Low voltage ride through control of modular multilevel converter based hvdc s...Ghazal Falahi
Low Voltage Ride Through (LVRT) is an important grid requirement for Voltage Source Converter (VSC) based HVDC links. This paper studies the performance of the modular multilevel converter (MMC) VSC based HVDC systems during faults or voltage dips and proposes a new control strategy to improve the LVRT performance. The proposed algorithm controls the system to generate the required active and reactive powers that are calculated mathematically based on the ratings of the MMC-HVDC system and LVRT requirements. The injected active and reactive power values obey the LVRT guidelines and are adaptable to different grid codes. The mathematical calculations are presented and EMTDC/PSCAD simulation evaluates the performance of the proposed method.
International Journal of Computational Engineering Research(IJCER) ijceronline
nternational Journal of Computational Engineering Research (IJCER) is dedicated to protecting personal information and will make every reasonable effort to handle collected information appropriately. All information collected, as well as related requests, will be handled as carefully and efficiently as possible in accordance with IJCER standards for integrity and objectivity.
Influence of Skidded Distance on the Initial Velocity of Vehicle in Chain Acc...IJMER
International Journal of Modern Engineering Research (IJMER) is Peer reviewed, online Journal. It serves as an international archival forum of scholarly research related to engineering and science education.
In this paper the finite element analysis of aHeat Exchanger is done. The geometry was
modelled in CATI A V5 R21 and finite element analysis had been performed in ANSYS12 WB. FE analysis
is was used to determine stress analysis at.
Cost Analysis of Small Scale Solar and Wind Energy SystemsIJMER
Abstract: The recent dramatic increase in the use of
renewable energy systems leading towards competitive
markets within the various individual renewable energy
systems. The aim of this paper is to prove the hypothesis
i.e. in next few years, when the cost of the solar PV
modules come down below 1$ per Watt, small wind
turbines become more costlier because of the cost of
structures required to support the wind generator. And
also if the threat from the market is not addressed both
technically and commercially, small wind turbine
manufactures will lose the competition to solar PV module
manufactures in the near visible future. Objective of this
paper is to do cost analysis on the industry data and prove
hypothesis and to arrive at the cutoff point, where after the
generating energy from the wind is not economically
feasible. With this cost analysis, author here by alarm for
the small scale wind turbine manufactures to take
necessary measures to survive the competitive markets of
small scale renewable energy systems.
Keywords: Renewable energy, Solar PV, Wind Turbine, Curve Fitting, Cost analysis.
An Inclusive Analysis on Various Image Enhancement TechniquesIJMER
Digital Image enhancement is the process of adjusting digital images so that the results are
more suitable for display or further image analysis. It provides a multitude of choices for improving the
visual quality of images or to provide a “better transform representation for future automated image
processing. The enhancement technique differs from one field to another field. The existing techniques
of image enhancement can be classified into two categories: Spatial Domain and Frequency domain
enhancement. Many images like satellite images, medical images, aerial images and even real life
photographs suffer from poor contrast and noise. It improves the quality (clarity) of images for human
viewing by eradicating blurs, noise, increasing contrast, and revealing image details.
The Effect of Design Parameters of an Integrated Linear Electromagnetic Moto...IJMER
This paper assess the influence of design parameters of ferromagnetic guide housing at the possess of pulling away the anchor from the holding device which is integrated in the design of the motor. The design of an integrated circuit and the equivalent magnetic circuit of the integrated LEMM on breakaway stage was built, mathematical models of system were laid out. An expression for its magnetic
induction, with which you can set the beginning of saturation of the shunt, defining moment of pulling
away anchor from the holding area. an expression is derived for its magnetic induction, with which you
can set the beginning of saturation of the shunt, define moment of anchor pulling away from the holding
area, the zone of permissible combinations of cross-sectional area of the upper magnetic shunt and
holding area, and the zone of change in the magnetic induction in the yoke at the pulling away moment of
the motor anchor
A Novel Data mining Technique to Discover Patterns from Huge Text CorpusIJMER
Today, we have far more information than we can handle: from business transactions and scientific
data, to satellite pictures, text reports and military intelligence. Information retrieval is simply not enough
anymore for decision-making. Confronted with huge collections of data, we have now created new needs to
help us make better managerial choices. These needs are automatic summarization of data, extraction of the
"essence" of information stored, and the discovery of patterns in raw data. With this, Data mining with
inventory pattern came into existence and got popularized. Data mining finds these patterns and relationships
using data analysis tools and techniques to build models.
Crack Detection of Ferromagnetic Materials through Non Destructive Testing Me...IJMER
The real components have so many defects in the material, which acts as a crack. In fact,
manufacturing of a component is not ideal. In manufacturing several kinds of defects are generated
like voids and inclusions. Thus, it must be check all the critical components through non-destructive
techniques (NDT) to detect the potential dangerous cracks. In Certain crucial components such as
Airplanes, Space Vehicles, Nuclear Plants, Heavy Machinery, Dams, Concrete etc., online monitoring
of defects is necessary. Concrete is different from other construction materials. Concrete can be made
from combination of different materials. Its final properties depend on its treatment at construction
site. To achieve this, sophisticated technologies are used. Ferromagnetic Composite Iron (FCI) is
used in power generating devices and DC brushless Motors. Laminations can be substituted by
Ferromagnetic Composite Iron (FCI) materials which offer a great manufacturing advantage. Non
Destructive testing (NDT) is a major part of quality control. In Non-Destructive testing (NDT)
different materials are tested for surface, volumetric and internal defects present in it. Non
Destructive testing (NDT) is also an assurance that the proposed product is good and reliable. To
apply these techniques, a certain level of skills is very necessary so that maximum amount of
information is fetched related to the proposed product during testing. This paper deals with the Non
Destructive Testing Methodology Used for crack detection in ferromagnetic materials.
Virtualization Technology using Virtual Machines for Cloud ComputingIJMER
Cloud computing is the delivery of computing and storage capacity as a service to a community of end users. The name “cloud computing” comes from the use of a cloud-shaped symbol as an abstraction for the complex infrastructure it contains in system diagrams. Cloud computing entrusts services with a user's software, data and computation over a network. End users access cloud-based applications through a web browser or mobile application or a light-weight desktop while the business software and user's data are stored on servers at a remote location. Proponents claim that cloud computing environment allows enterprises to get their applications up and running faster, with improved manageability and less maintenance, and enables IT industry to more rapidly adjust resources to meet fluctuating and unpredictable business demand. In this paper, we present a system that uses virtualization technology to allocate the data center resources dynamically based on the application demands and support green computing by optimizing the number of servers in use. This method multiplexes virtual to physical resources adaptively based on the changing demand. We use the concept of skewness metric to combine virtual machines with different resource characteristics appropriately so that the capacities of servers are well utilized.
Optimization of Surface Impedance for Reducing Surface Waves between AntennasIJMER
International Journal of Modern Engineering Research (IJMER) is Peer reviewed, online Journal. It serves as an international archival forum of scholarly research related to engineering and science education.
International Journal of Modern Engineering Research (IJMER) is Peer reviewed, online Journal. It serves as an international archival forum of scholarly research related to engineering and science education.
International Journal of Modern Engineering Research (IJMER) covers all the fields of engineering and science: Electrical Engineering, Mechanical Engineering, Civil Engineering, Chemical Engineering, Computer Engineering, Agricultural Engineering, Aerospace Engineering, Thermodynamics, Structural Engineering, Control Engineering, Robotics, Mechatronics, Fluid Mechanics, Nanotechnology, Simulators, Web-based Learning, Remote Laboratories, Engineering Design Methods, Education Research, Students' Satisfaction and Motivation, Global Projects, and Assessment…. And many more.
International Journal of Engineering Research and DevelopmentIJERD Editor
Electrical, Electronics and Computer Engineering,
Information Engineering and Technology,
Mechanical, Industrial and Manufacturing Engineering,
Automation and Mechatronics Engineering,
Material and Chemical Engineering,
Civil and Architecture Engineering,
Biotechnology and Bio Engineering,
Environmental Engineering,
Petroleum and Mining Engineering,
Marine and Agriculture engineering,
Aerospace Engineering.
International Journal of Engineering Research and DevelopmentIJERD Editor
Electrical, Electronics and Computer Engineering,
Information Engineering and Technology,
Mechanical, Industrial and Manufacturing Engineering,
Automation and Mechatronics Engineering,
Material and Chemical Engineering,
Civil and Architecture Engineering,
Biotechnology and Bio Engineering,
Environmental Engineering,
Petroleum and Mining Engineering,
Marine and Agriculture engineering,
Aerospace Engineering.
International Journal of Engineering Research and Development is an international premier peer reviewed open access engineering and technology journal promoting the discovery, innovation, advancement and dissemination of basic and transitional knowledge in engineering, technology and related disciplines.
Flexible alternating current transmission systems (FACTs) technology opens up new opportunities for
controlling power flow and enhancing the usable capacity of present, as well as new and upgraded lines. These
FACTs device which enables independent control of active and reactive power besides improving reliability and
quality of the supply. This paper describes the real and reactive power flow control through a short transmission
line and then compensated short transmission line with different FACTs devices are used to selection of FACTs
devices for better reactive power compensation with change in line capacitance/shunt capacitance to observe
power flow. Computer simulation by MATLAB/SIMULINK has been used to determining better reactive power.
TCSC, STATCOM, UPFC and SSSC FACTs controller with different capacitance are tested for controlling
reactive power flow.
Static Sustenance of Power System Stability Using FLC Based UPFC in SMIB Powe...IJMER
International Journal of Modern Engineering Research (IJMER) is Peer reviewed, online Journal. It serves as an international archival forum of scholarly research related to engineering and science education.
International Journal of Modern Engineering Research (IJMER) covers all the fields of engineering and science: Electrical Engineering, Mechanical Engineering, Civil Engineering, Chemical Engineering, Computer Engineering, Agricultural Engineering, Aerospace Engineering, Thermodynamics, Structural Engineering, Control Engineering, Robotics, Mechatronics, Fluid Mechanics, Nanotechnology, Simulators, Web-based Learning, Remote Laboratories, Engineering Design Methods, Education Research, Students' Satisfaction and Motivation, Global Projects, and Assessment…. And many more.
International Journal of Engineering Research and Applications (IJERA) is an open access online peer reviewed international journal that publishes research and review articles in the fields of Computer Science, Neural Networks, Electrical Engineering, Software Engineering, Information Technology, Mechanical Engineering, Chemical Engineering, Plastic Engineering, Food Technology, Textile Engineering, Nano Technology & science, Power Electronics, Electronics & Communication Engineering, Computational mathematics, Image processing, Civil Engineering, Structural Engineering, Environmental Engineering, VLSI Testing & Low Power VLSI Design etc.
The increase in power demand has compelled the power system utilities to use series capacitive compensation in long transmission lines.
A problem called sub synchronous resonance (SSR) occurs in long lines because of series compensation. In this paper a flexible a.c. transmission
system (FACTS) device is used along with a proposed controller to damp out the sub synchronous oscillations from the system. An IEEE second
bench mark model is used for investigating the SSR problem, where a three phase short circuit fault is applied on the compensated transmission
line for analysis. A Matlab/Simulink model is used to study the time domain analysis of the system. An improvement in damping is seen with the
use of FACTS device i.e. unified power flow controller (UPFC) which is controlled by a Neural network (NN) based proportional integral (PI)
controller
Transient Stability of Power System using Facts Device-UPFCijsrd.com
This paper is based on Occurrence of a fault in a power system causes transients. To stabilize the system, The Flexible Alternating Current Transmission (FACTS) devices such as UPFC are becoming important in suppressing power system oscillations and improving system damping. The UPFC is a solid-state device, which can be used to control the active and reactive power.. By using a UPFC the oscillation introduced by the faults, the rotor angle and speed deviations can be damped out quickly than a system without a UPFC. The effectiveness of UPFC in suppressing power system oscillation is investigated by analyzing their oscillation in rotor angle and change in speed occurred in the two machine system considered in this work. A proportional integral (PI) controller has been employed for the UPFC. It is also shown that a UPFC can control independently the real and reactive power flow in a transmission line. A MATLAB simulation has been carried out to demonstrate the performance of the UPFC in achieving transient stability of the two-machine five-bus system.
Enhancement of Power System Dynamics Using a Novel Series Compensation SchemeIJMER
Phase imbalanced capacitive compensation is a “hybrid” series compensation scheme, where the
series capacitive compensation in one phase is created using a single-phase TCSC in series with a fixed capacitor
(Cc), and the other two phases are compensated by fixed series capacitors (C). The TCSC control is initially set
such that its equivalent compensations at the power frequency combined with the fixed capacitor yield a
resultant compensation equal to the other two phases. Thus, the phase balance is maintained at the power
frequency while at any other frequency, a phase imbalance is created. The effectiveness of the scheme in damping
power system oscillations for various network conditions, namely different system faults and tie-line power flows is
evaluated using the MATLAB/SIMULINK Software
Design and Analysis of Adaptive Neural Controller for Voltage Source Converte...IDES Editor
Usually a STATCOM is installed to support power
system networks that have a poor power factor and often poor
voltage regulation. It is based on a power electronics voltagesource
converter. Various PWM techniques make selective
harmonic elimination possible, which effectively control the
harmonic content of voltage source converters. The distribution
systems have to supply unbalanced nonlinear loads transferring
oscillations to the DC-side of the converter in a realistic
operating condition. Thus, additional harmonics are modulated
through the STATCOM at the point of common coupling
(PCC). This requires more attention when switching angles are
calculated offline using the optimal PWM technique. This
paper, therefore, presents the artificial neural network model
for defining the switching criterion of the VSC for the
STATCOM in order to reduce the total harmonic distortion
(THD) of the injected line current at the PCC. The model takes
into the account the dc capacitor effect, effects of other possible
varying parameters such as voltage unbalance as well as
network harmonics. A reference is developed for offline
prediction and then implemented with the help of back
propagation technique.
A New Approach to Powerflow Management in Transmission System Using Interline...IJERA Editor
In this paper a new approach to power flow management in transmission system using interline Power Flow
Controller (IPFC) is proposed and model for IPFC is developed and simulate by MATLAB software. Interline
Power Flow Controller is a versatile device can be used to control power flows of a multi-line system or subnetworks
An Interline Power Flow Controller (IPFC) is a converter based FACTS controller for series
compensation with capability of controlling power flow among multi-lines within the same corridor of the
transmission line. It consists of two or more Voltage Source Converters (VSCs) with a common dc-link. Real
power can be transferred via the common dc-link between the VSCs and each VSC is capable of exchanging
reactive power with its own transmission system
International Journal of Engineering Research and Applications (IJERA) is an open access online peer reviewed international journal that publishes research and review articles in the fields of Computer Science, Neural Networks, Electrical Engineering, Software Engineering, Information Technology, Mechanical Engineering, Chemical Engineering, Plastic Engineering, Food Technology, Textile Engineering, Nano Technology & science, Power Electronics, Electronics & Communication Engineering, Computational mathematics, Image processing, Civil Engineering, Structural Engineering, Environmental Engineering, VLSI Testing & Low Power VLSI Design etc.
A Study on Translucent Concrete Product and Its Properties by Using Optical F...IJMER
- Translucent concrete is a concrete based material with light-transferring properties,
obtained due to embedded light optical elements like Optical fibers used in concrete. Light is conducted
through the concrete from one end to the other. This results into a certain light pattern on the other
surface, depending on the fiber structure. Optical fibers transmit light so effectively that there is
virtually no loss of light conducted through the fibers. This paper deals with the modeling of such
translucent or transparent concrete blocks and panel and their usage and also the advantages it brings
in the field. The main purpose is to use sunlight as a light source to reduce the power consumption of
illumination and to use the optical fiber to sense the stress of structures and also use this concrete as an
architectural purpose of the building
Developing Cost Effective Automation for Cotton Seed DelintingIJMER
A low cost automation system for removal of lint from cottonseed is to be designed and
developed. The setup consists of stainless steel drum with stirrer in which cottonseeds having lint is mixed
with concentrated sulphuric acid. So lint will get burn. This lint free cottonseed treated with lime water to
neutralize acidic nature. After water washing this cottonseeds are used for agriculter purpose
Study & Testing Of Bio-Composite Material Based On Munja FibreIJMER
The incorporation of natural fibres such as munja fiber composites has gained
increasing applications both in many areas of Engineering and Technology. The aim of this study is to
evaluate mechanical properties such as flexural and tensile properties of reinforced epoxy composites.
This is mainly due to their applicable benefits as they are light weight and offer low cost compared to
synthetic fibre composites. Munja fibres recently have been a substitute material in many weight-critical
applications in areas such as aerospace, automotive and other high demanding industrial sectors. In
this study, natural munja fibre composites and munja/fibreglass hybrid composites were fabricated by a
combination of hand lay-up and cold-press methods. A new variety in munja fibre is the present work
the main aim of the work is to extract the neat fibre and is characterized for its flexural characteristics.
The composites are fabricated by reinforcing untreated and treated fibre and are tested for their
mechanical, properties strictly as per ASTM procedures.
Hybrid Engine (Stirling Engine + IC Engine + Electric Motor)IJMER
Hybrid engine is a combination of Stirling engine, IC engine and Electric motor. All these 3 are
connected together to a single shaft. The power source of the Stirling engine will be a Solar Panel. The aim of
this is to run the automobile using a Hybrid engine
Fabrication & Characterization of Bio Composite Materials Based On Sunnhemp F...IJMER
The present day technology demands eco-friendly developments. In this era the
composite material are playing a vital roal in different field of Engineering .The composite materials
are using as a principle materials. Nowaday the composite materials are utilizing as a important
component of engineering field .Where as the importance of the applications of composites is well
known, but thrust on the use of natural fibres in it for reinforcement has been given priority for some
times. But changing from synthetic fibres to natural fibres provides only half green-composites. A
partial green composite will be achieved if the matrix component is also eco-friendly. Keeping this in
view, a detailed literature surveyed has been carried out through various issues of the Journals
related to this field. The material systems used are sunnhemp fibres. Some epoxy and hardener has
been also added for stability and drying of the bio-composites. Various graphs and bar-charts are
super-imposed on each other for comparison among themselves and Graphs is plotted on MAT LAB
and ORIGIN 6.0 software. To determining tensile strengths, Various properties for different biocomposites
have been compared among themselves. Comparison of the behaviour of bio-composites of
this work has been also compare with other works. The bio-composites developed in this work are
likely to get applications in fall ceilings, partitions, bio-degradable packagings, automotive interiors,
sports things (e.g. rackets, nets, etc.), toys etc.
Geochemistry and Genesis of Kammatturu Iron Ores of Devagiri Formation, Sandu...IJMER
The Greenstone belts of Karnataka are enriched in BIFs in Dharwar craton, where Iron
formations are confined to the basin shelf, clearly separated from the deeper-water iron formation that
accumulated at the basin margin and flanking the marine basin. Geochemical data procured in terms of
major, trace and REE are plotted in various diagrams to interpret the genesis of BIFs. Al2O3, Fe2O3 (T),
TiO2, CaO, and SiO2 abundances and ratios show a wide variation. Ni, Co, Zr, Sc, V, Rb, Sr, U, Th,
ΣREE, La, Ce and Eu anomalies and their binary relationships indicate that wherever the terrigenous
component has increased, the concentration of elements of felsic such as Zr and Hf has gone up. Elevated
concentrations of Ni, Co and Sc are contributed by chlorite and other components characteristic of basic
volcanic debris. The data suggest that these formations were generated by chemical and clastic
sedimentary processes on a shallow shelf. During transgression, chemical precipitation took place at the
sediment-water interface, whereas at the time of regression. Iron ore formed with sedimentary structures
and textures in Kammatturu area, in a setting where the water column was oxygenated.
Experimental Investigation on Characteristic Study of the Carbon Steel C45 in...IJMER
In this paper, the mechanical characteristics of C45 medium carbon steel are investigated
under various working conditions. The main characteristic to be studied on this paper is impact toughness
of the material with different configurations and the experiment were carried out on charpy impact testing
equipment. This study reveals the ability of the material to absorb energy up to failure for various
specimen configurations under different heat treated conditions and the corresponding results were
compared with the analysis outcome
Non linear analysis of Robot Gun Support Structure using Equivalent Dynamic A...IJMER
Robot guns are being increasingly employed in automotive manufacturing to replace
risky jobs and also to increase productivity. Using a single robot for a single operation proves to be
expensive. Hence for cost optimization, multiple guns are mounted on a single robot and multiple
operations are performed. Robot Gun structure is an efficient way in which multiple welds can be done
simultaneously. However mounting several weld guns on a single structure induces a variety of
dynamic loads, especially during movement of the robot arm as it maneuvers to reach the weld
locations. The primary idea employed in this paper, is to model those dynamic loads as equivalent G
force loads in FEA. This approach will be on the conservative side, and will be saving time and
subsequently cost efficient. The approach of the paper is towards creating a standard operating
procedure when it comes to analysis of such structures, with emphasis on deploying various technical
aspects of FEA such as Non Linear Geometry, Multipoint Constraint Contact Algorithm, Multizone
meshing .
Static Analysis of Go-Kart Chassis by Analytical and Solid Works SimulationIJMER
This paper aims to do modelling, simulation and performing the static analysis of a go
kart chassis consisting of Circular beams. Modelling, simulations and analysis are performed using 3-D
modelling software i.e. Solid Works and ANSYS according to the rulebook provided by Indian Society of
New Era Engineers (ISNEE) for National Go Kart Championship (NGKC-14).The maximum deflection is
determined by performing static analysis. Computed results are then compared to analytical calculation,
where it is found that the location of maximum deflection agrees well with theoretical approximation but
varies on magnitude aspect.
In récent year various vehicle introduced in market but due to limitation in
carbon émission and BS Séries limitd speed availability vehicle in the market and causing of
environnent pollution over few year There is need to decrease dependancy on fuel vehicle.
bicycle is to be modified for optional in the future To implement new technique using change in
pedal assembly and variable speed gearbox such as planetary gear optimise speed of vehicle
with variable speed ratio.To increase the efficiency of bicycle for confortable drive and to
reduce torque appli éd on bicycle. we introduced epicyclic gear box in which transmission done
throgh Chain Drive (i.e. Sprocket )to rear wheel with help of Epicyclical gear Box to give
number of différent Speed during driving.To reduce torque requirent in the cycle with change in
the pedal mechanism
Integration of Struts & Spring & Hibernate for Enterprise ApplicationsIJMER
The proposal of this paper is to present Spring Framework which is widely used in
developing enterprise applications. Considering the current state where applications are developed using
the EJB model, Spring Framework assert that ordinary java beans(POJO) can be utilize with minimal
modifications. This modular framework can be used to develop the application faster and can reduce
complexity. This paper will highlight the design overview of Spring Framework along with its features that
have made the framework useful. The integration of multiple frameworks for an E-commerce system has
also been addressed in this paper. This paper also proposes structure for a website based on integration of
Spring, Hibernate and Struts Framework.
Microcontroller Based Automatic Sprinkler Irrigation SystemIJMER
Microcontroller based Automatic Sprinkler System is a new concept of using
intelligence power of embedded technology in the sprinkler irrigation work. Designed system replaces
the conventional manual work involved in sprinkler irrigation to automatic process. Using this system a
farmer is protected against adverse inhuman weather conditions, tedious work of changing over of
sprinkler water pipe lines & risk of accident due to high pressure in the water pipe line. Overall
sprinkler irrigation work is transformed in to a comfortableautomatic work. This system provides
flexibility & accuracy in respect of time set for the operation of a sprinkler water pipe lines. In present
work the author has designed and developed an automatic sprinkler irrigation system which is
controlled and monitored by a microcontroller interfaced with solenoid valves.
On some locally closed sets and spaces in Ideal Topological SpacesIJMER
In this paper we introduce and characterize some new generalized locally closed sets
known as
δ
ˆ
s-locally closed sets and spaces are known as
δ
ˆ
s-normal space and
δ
ˆ
s-connected space and
discussed some of their properties
Intrusion Detection and Forensics based on decision tree and Association rule...IJMER
This paper present an approach based on the combination of, two techniques using
decision tree and Association rule mining for Probe attack detection. This approach proves to be
better than the traditional approach of generating rules for fuzzy expert system by clustering methods.
Association rule mining for selecting the best attributes together and decision tree for identifying the
best parameters together to create the rules for fuzzy expert system. After that rules for fuzzy expert
system are generated using association rule mining and decision trees. Decision trees is generated for
dataset and to find the basic parameters for creating the membership functions of fuzzy inference
system. Membership functions are generated for the probe attack. Based on these rules we have
created the fuzzy inference system that is used as an input to neuro-fuzzy system. Fuzzy inference
system is loaded to neuro-fuzzy toolbox as an input and the final ANFIS structure is generated for
outcome of neuro-fuzzy approach. The experiments and evaluations of the proposed method were
done with NSL-KDD intrusion detection dataset. As the experimental results, the proposed approach
based on the combination of, two techniques using decision tree and Association rule mining
efficiently detected probe attacks. Experimental results shows better results for detecting intrusions as
compared to others existing methods
Natural Language Ambiguity and its Effect on Machine LearningIJMER
"Natural language processing" here refers to the use and ability of systems to process
sentences in a natural language such as English, rather than in a specialized artificial computer
language such as C++. The systems of real interest here are digital computers of the type we think of as
personal computers and mainframes. Of course humans can process natural languages, but for us the
question is whether digital computers can or ever will process natural languages. We have tried to
explore in depth and break down the types of ambiguities persistent throughout the natural languages
and provide an answer to the question “How it affects the machine translation process and thereby
machine learning as whole?” .
Today in era of software industry there is no perfect software framework available for
analysis and software development. Currently there are enormous number of software development
process exists which can be implemented to stabilize the process of developing a software system. But no
perfect system is recognized till yet which can help software developers for opting of best software
development process. This paper present the framework of skillful system combined with Likert scale. With
the help of Likert scale we define a rule based model and delegate some mass score to every process and
develop one tool name as MuxSet which will help the software developers to select an appropriate
development process that may enhance the probability of system success.
Material Parameter and Effect of Thermal Load on Functionally Graded CylindersIJMER
The present study investigates the creep in a thick-walled composite cylinders made
up of aluminum/aluminum alloy matrix and reinforced with silicon carbide particles. The distribution
of SiCp is assumed to be either uniform or decreasing linearly from the inner to the outer radius of
the cylinder. The creep behavior of the cylinder has been described by threshold stress based creep
law with a stress exponent of 5. The composite cylinders are subjected to internal pressure which is
applied gradually and steady state condition of stress is assumed. The creep parameters required to
be used in creep law, are extracted by conducting regression analysis on the available experimental
results. The mathematical models have been developed to describe steady state creep in the composite
cylinder by using von-Mises criterion. Regression analysis is used to obtain the creep parameters
required in the study. The basic equilibrium equation of the cylinder and other constitutive equations
have been solved to obtain creep stresses in the cylinder. The effect of varying particle size, particle
content and temperature on the stresses in the composite cylinder has been analyzed. The study
revealed that the stress distributions in the cylinder do not vary significantly for various combinations
of particle size, particle content and operating temperature except for slight variation observed for
varying particle content. Functionally Graded Materials (FGMs) emerged and led to the development
of superior heat resistant materials.
Energy Audit is the systematic process for finding out the energy conservation
opportunities in industrial processes. The project carried out studies on various energy conservation
measures application in areas like lighting, motors, compressors, transformer, ventilation system etc.
In this investigation, studied the technical aspects of the various measures along with its cost benefit
analysis.
Investigation found that major areas of energy conservation are-
1. Energy efficient lighting schemes.
2. Use of electronic ballast instead of copper ballast.
3. Use of wind ventilators for ventilation.
4. Use of VFD for compressor.
5. Transparent roofing sheets to reduce energy consumption.
So Energy Audit is the only perfect & analyzed way of meeting the Industrial Energy Conservation.
An Implementation of I2C Slave Interface using Verilog HDLIJMER
The focus of this paper is on implementation of Inter Integrated Circuit (I2C) protocol
following slave module for no data loss. In this paper, the principle and the operation of I2C bus protocol
will be introduced. It follows the I2C specification to provide device addressing, read/write operation and
an acknowledgement. The programmable nature of device provide users with the flexibility of configuring
the I2C slave device to any legal slave address to avoid the slave address collision on an I2C bus with
multiple slave devices. This paper demonstrates how I2C Master controller transmits and receives data to
and from the Slave with proper synchronization.
The module is designed in Verilog and simulated in ModelSim. The design is also synthesized in Xilinx
XST 14.1. This module acts as a slave for the microprocessor which can be customized for no data loss.
Discrete Model of Two Predators competing for One PreyIJMER
This paper investigates the dynamical behavior of a discrete model of one prey two
predator systems. The equilibrium points and their stability are analyzed. Time series plots are obtained
for different sets of parameter values. Also bifurcation diagrams are plotted to show dynamical behavior
of the system in selected range of growth parameter
Discrete Model of Two Predators competing for One Prey
Nonlinear Control of UPFC in Power System for Damping Inter Area Oscillations
1. International Journal of Modern Engineering Research (IJMER)
www.ijmer.com Vol.2, Issue.6, Nov-Dec. 2012 pp-4266-4272 ISSN: 2249-6645
Nonlinear Control of UPFC in Power System for Damping Inter
Area Oscillations
1
M.Praveen Kumar, 2P B Chennaiah
1
EEE,M.Tech student, AITS, Rajampet, Kadapa , A.P, India,
2
EEE, Associate Professor, AITS, Rajampet,Kadapa, A.P, India,
Abstract: This paper introduces a new nonlinear control Therefore developing suitable control strategies is
of flexible ac transmission systems (FACTS) controllers for a requirement before FACTS can be confidently utilized in
the purpose of damping interarea oscillations in power the power system. Several authors have investigated
systems. FACTS controllers consist of series, shunt, or a utilizing FACTS, especially UPFCs to damp interarea
combination of series-shunt devices which are interfaced oscillations using a variety of control approaches [1]–[10].
with the bulk power system through injection buses. Interarea oscillations can occur in a system because of
Controlling the angle of these buses can effectively damp contingencies such as sudden load changes or faults. In [1]–
low frequency interarea oscillations in the system. The [5], oscillation damping is based on a linear control
proposed control method is based on finding an equivalent approach to the UPFC and power system, whereas other
reduced affine nonlinear system for the network from which authors consider nonlinear control systems theory and
the dominant machines are extracted based on dynamic Lyapunov Energy Functions [6]–[10]. Typically, nonlinear
coherency. It is shown that if properly selected, approaches are more effective for large perturbations or
measurements obtained from this subsystem of machines when the power system state strays significantly from the
are sufficient inputs to the FACTS controllers to stabilize initial operating point.
the power system. The effectiveness of the proposed method
on damping interarea oscillations is validated on the 68 The approach proposed in this paper provides
bus, 16 generator system of the New England/New York a general nonlinear method for using multiple FACTS
network. controllers in a power network for the purpose of damping
interarea oscillations. In this paper, it is shown that any
IndexTerms: Coherent groups, dominant machines, FACTS device capable of changing its interface bus
flexible ac transmission systems (FACTS), interarea angle(s) with the network can be used to mitigate power
oscillation, nonlinear control, phasor measurement unit system oscillations. Using this method, it will be shown that
(PMU), wide-area control. both shunt and series FACTS controllers can be used for
this purpose. The control method is based on finding a
I. INTRODUCTION reduced nonlinear affine state space system for the network
which can be controlled by feedback of selected
AS high voltage power electronics become less measurements of rotor frequencies. While frequency
expensive and have a wider-range of operation, flexible ac measurements (such as from FNET [11]) have made wide
transmission systems (FACTS) controllers will become area control of the power networks feasible, it is still not
more prevalent in the transmission system to control active reasonable to expect that the full set of frequency
power flow across congested corridors and ensure voltage measurements is available for controller use. Therefore, an
security. In addition, FACTS controllers can provide approach is proposed to use a reduced set of measurements
promising solutions to many of the stability problems that from a subset of machines in the system.
occur within the bulk power system. FACTS controllers can II. UPFC MODEL
be categorized into three major groups: shunt devices such
as the Static Synchronous Compensator (STATCOM), The UPFC is the most versatile FACTS device. It
series devices such as the static synchronous series consists of a combination of a shunt and series branches
compensator (SSSC) and series shunt devices such as the connected through the DC capacitor as shown in Fig. 1.
unified power flow controller (UPFC). In addition to Models for the STATCOM and SSSC can be easily
steady-state solutions such as power flow and voltage extracted from the UPFC model by considering the shunt
control, an added benefit of FACTS controllers deployed in and series converters individually. The series connected
the transmission system is that they can also effectively inverter injects a voltage with controllable magnitude and
Control active power oscillations that can damage phase angle in series with the transmission line, therefore
generators, increase line losses, and increase wear and tear providing active and reactive power to the transmission
on network components. line. The shunt-connected inverter
www.ijmer.com 4266 | Page
2. International Journal of Modern Engineering Research (IJMER)
www.ijmer.com Vol.2, Issue.6, Nov-Dec. 2012 pp-4266-4272 ISSN: 2249-6645
Fig.1. Unified power flow controller diagram.
Provides the active power drawn by the series branch plus
the losses and can independently provide reactive
compensation to the system. The UPFC model is given by
[12] as shown in (1)–(5) at the bottom of the next page,
where the parameters are as shown in Fig. 1. The currents
and are the components of the shunt
current. The currents and are the
components of the series current. The voltages
and are the sending end and receiving end
voltage magnitudes and angles, respectively. The UPFC is
controlled by varying the phase angles ( ) and (
Fig. 2. Equivalent power system from the controller
) magnitudes of the converter shunt and series viewpoint.
output voltages ( ), respectively. Using the load impedance model, the only points of current
The power balance equations at bus 1 are given by injection into the network are the generator internal buses
and the UPFC sending and receiving end buses. Using
Kron reduction, the transmission network can be reduced
to an admittance matrix of size ( ) whereN
………………(1) is the number of generator buses and is the number FACTS
current injections in the system. Fig. 2 illustrates the
reduced system showing the points of current injection.
……………. (2) Each UPFC has two current injections and , at the
sending and receiving ends, respectively; a STATCOM
and at bus 2 and SSSC have only one current. The generator current
injections are given by .
The classical model for the reduced network
……(3) including the UPFCs.
Mechanical power, inertia constant and angular speed,
respectively, of machine; and is synchronous speed. The
………(4) summation represents the active power injected at each
current injection point, including FACTS buses.
IV. CONTROLLER DESIGN
III. SYSTEM MODEL
For control development purposes, several The controller design consists of three stages.
initial assumptions are made. The first assumption is that A. Stage I
the system loads are modeled as constant impedance loads The objective of the first design stage is to find
the desired changes in mechanical powers required to
and can therefore be absorbed into the bus admittance
matrix. Second, the generators are modeled as the classical stabilize the system. To obtain the amount of mechanical
―transient reactance behind constant voltage‖ model. Note power required, it is initially assumed that the mechanical
that these assumptions are for control development only— powers ,are inputs into the system model. Note that
the proposed control is validated with the full nonlinear 10- this is only for controller development; in the final control,
th order power system model given in the Appendix [13]. it is not required that the generator mechanical powers
In addition, the proposed control is developed for the actually vary.
UPFC; control development for the STATCOM and SSSC Under this assumption, the system models are
follows a similar procedure and is therefore not explicitly ……………………… (5)
detailed.
www.ijmer.com 4267 | Page
3. International Journal of Modern Engineering Research (IJMER)
www.ijmer.com Vol.2, Issue.6, Nov-Dec. 2012 pp-4266-4272 ISSN: 2249-6645
where as shown in (13)–(15) at the bottom of the page and affine nonlinear system, the output 𝑦(𝑡) tracks a prescribed
. reference value 𝜔 𝑡 in terms of a given performance:
Since it is only required that the system frequencies return
to steady-state rapidly, a subset of (12) is 𝑥 = 𝑓(𝑥 𝑡 ) + 𝑔 𝑥 𝑡 𝑢(𝑡) ………..(14)
…………………….(6)
where and 𝑦 𝑖 𝑡 = 𝑖 (𝑥 𝑡 ) i=1,….,m ………….(15)
Where 𝑚 is the number of outputs equal to the number of
inputs in 𝑢(𝑡) . The receding horizon performance index is
given by
where ..(7)
1
⋯ 0 1 𝑇
𝐽 = 2 0 (𝑦 (𝑡 + 𝜏) − 𝜔(𝑡 + 𝜏))𝑑𝜏 × (𝑦 𝑡 + 𝜏 − 𝜔(𝑡 +
𝑀1
𝑔 = ⋮ ⋱ ⋮ …………………….(8) 𝜏))𝑑𝜏 ………….(16)
1
0 ⋯ 𝑀1 whereT is the predictive period. The actual control
𝑢 = [𝑃𝑚1 𝑃𝑚2 … 𝑃𝑚𝑛 ] input 𝑢(𝑡) is given by the initial value of the optimal
Letting x1s ,x2s , and us denote the steady-state values control input 𝑢(𝑡 + 𝜏) for 0 ≤ 𝜏 ≤T and 𝑢(𝑡 + 𝜏) when
ofx1 ,x2 and u , respectively, then the error in generator 𝜏 =0.
rotor frequencies becomes The optimal predictive control law is given by
е = x2-x2s…………..(9)
𝑝−1 𝜌
and 𝑢 𝑡 = −(𝐿 𝑔 𝑙 𝑓 (𝑥))−1 (𝐾𝑀 𝜌 + 𝐿 𝑓 𝑥 − 𝜔 𝜌
(𝑡)
ė = f(x)-f(x1s)-gus+gud……………(10) ……..(17)
Equation (21) can be stabilized with input 𝑢𝑑so that
𝑢 𝑑 = 𝑔−1 [-f(𝑥1 )+f(𝑥1𝑠 )-𝑔𝑢 𝑠 +Ke]………..(11) where𝜌 is the relative degree for the system outputs
(assuming that all outputs have the same relative degree)
where K is a positive definite matrix and and 𝐿 is the Lie derivative defined by
𝑒 . = −𝐾𝑒…………..(12)
B. Stage II 𝜕𝑣
𝐿𝜇 𝑣 = 𝜇 ……..(18)
In Stage I, the required changes in the generator’s 𝜕𝑥
mechanical powers were found that stablize the system. In
Stage II, these changes are translated into control signals to The matrix 𝐾 is given by
the FACTS controllers. As noted previously, the generator
mechanical powers do not actually change as a
consequence of the proposed control. Therefore, using the
desired active power changes, a new control signal is
introduced
⊿𝑢 = 𝑢 𝑑𝑒𝑠𝑖𝑟𝑒𝑑 − 𝑢 𝑎𝑐𝑡𝑢𝑎𝑙 ……….(13)
Where 𝑢 𝑑𝑒𝑠𝑖𝑟𝑒𝑑 and 𝑢 𝑎𝑐𝑡𝑢𝑎𝑙 are the desired and ………….(19)
actual values for the generator mechanical powers. This The matrix K is the first rows of the matrix 𝜓 −1 𝜓 𝜌𝑟 where
𝑟𝑟
𝑇
mismatch is translated into the desired changes in the
FACTS’ bus voltage angles, as shown in (25) at the bottom 𝜓(𝜌+1,𝜌+1) ⋯ 𝜓(𝜌+1,𝜌+𝑟+1)
of the page, where 𝜓 𝑟𝑟 = ………(20)
𝜓(𝜌,𝜌+1) ⋯ 𝜓(𝜌+𝑟+1,𝜌+𝑟 +1)
𝐿 = [𝑙1,….………𝑙 𝑁 ] 𝑇
∆= [∆𝛿1 , … . . ∆𝛿 𝑛 ] 𝑇 𝜓(1,𝜌+1) ⋯ 𝜓(1,𝜌+𝑟+1)
The nonlinear system is solved numerically for ∆. 𝜓 𝜌𝑟 = ……….(21)
𝜓(𝜌,𝜌+1) ⋯ 𝜓(𝜌,𝜌+𝑟+1)
Note that if 𝑁 ≠ 𝑛, then the system of equations is not Where
square and an exact solution is not possible. In this case,
the equations are solved to find the best fit to∆ which 𝑇 𝑖+𝑗 −1
minimizes the error. These values are then used to 𝜓 𝑖,𝑗 = , i, j=1,….,𝜌 + 𝑟 + 1 ……..(22)
𝑖−1 ! 𝑗 −1 ! 𝑖 +𝑗 −1 !
calculate the desired current injections 𝑖 ∗ 𝑑1 ,𝑖 ∗ 𝑞1 ,𝑖 ∗ 𝑑2
,𝑖 ∗ 𝑞2 from the power balance (1)–(4).
And
C. Stage III 𝑇 = 𝑑𝑖𝑎𝑔 𝑇, … . . , 𝑇 𝜖 𝑅 𝑚 ×𝑚
In Stage III, the desired current injections are Returning to (1)–(5), the relative degree for all of the
translated into actual control values for the FACTS outputs is 𝜌 = 1 and assuming the control order to be
controllers. As before, this approach is developed for the 𝑟 = 0, then the control law for the UPFC becomes
UPFC only, noting that similar approaches can be −3𝐿1 𝑅1 𝐿1
𝑢1 = 𝑖 − 𝑖∗ + 𝑖 − 𝑖 +
developed for the SSSC and STATCOM. To find the 𝜔 𝑠 𝑣 𝑑𝑐 𝑇 𝑑 1 𝑑1
𝑉 𝑑𝑐 𝑑1 𝑉 𝑑𝑐 𝑞1
actual control inputs, a predictive control based on [14] is 𝑉1 cos 𝜃1
+
𝐿1 𝑑 ∗
𝑖 𝑑1 ……….(23)
used. The basic methodology of predictive control is to 𝑉 𝑑𝑐 𝜔 𝑠 𝑉 𝑑𝑐 𝑑𝑡
design an asymptotically stable controller such that in an
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4. International Journal of Modern Engineering Research (IJMER)
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−3𝐿1 𝑅1 𝐿1 𝑉1 sin 𝜃1
𝑢2 = 𝑖 𝑞1 − 𝑖 ∗𝑞1 + 𝑖 𝑞1 − 𝑖 𝑑1 + +
𝜔 𝑠 𝑣 𝑑𝑐 𝑇 𝑉 𝑑𝑐 𝑉 𝑑𝑐 𝑉 𝑑𝑐
𝐿1 𝑑 ∗
𝑖 …….(24)
𝜔 𝑠 𝑉 𝑑𝑐 𝑑𝑡 𝑞1
−3𝐿1 𝑅1 𝐿1 𝑉2 cos 𝜃2
𝑢3 = 𝑖 𝑑 2 − 𝑖 ∗𝑑2 + 𝑖 𝑑2 − 𝑖 𝑞2 + −
𝜔 𝑠 𝑣 𝑑𝑐 𝑇 𝑉 𝑑𝑐 𝑉 𝑑𝑐 𝑉 𝑑𝑐
𝑉1 cos 𝜃1 𝐿2 𝑑
+ 𝑖 ∗𝑑2 ……..(25)
𝑉 𝑑𝑐 𝜔 𝑠 𝑉 𝑑𝑐 𝑑𝑡
−3𝐿2 𝑅2 𝐿2 𝑉2 sin 𝜃2
𝑢4 = 𝜔 𝑠 𝑣 𝑑𝑐 𝑇
𝑖 𝑞2 − 𝑖 ∗𝑞2 + 𝑉 𝑑𝑐
𝑖 𝑞2 − 𝑉 𝑑𝑐
𝑖 𝑑2 + 𝑉 𝑑𝑐
− Fig. 3. Three stage control process.
𝑉1 sin 𝜃1 𝐿1 𝑑
+ 𝑖 ∗𝑞1 ……..(26) 𝑢2
𝑉 𝑑𝑐 𝜔 𝑠 𝑉 𝑑𝑐 𝑑𝑡 𝛼1 = tan−1 ………(28)
𝑢1
2 2
These inputs are then translated into the control inputs for 𝑘2 = 𝑢3 + 𝑢4 ……(29)
−1 𝑢4
the UPFC 𝛼2 = tan ………….(30)
𝑢3
2 2
𝑘1 = 𝑢1 + 𝑢2 …………..(27)
The three stage control process and outcomes of each
stage are summarized in Fig.3
machines be ordered from 1 to Q and the rest of the
machines be numbered from Q+1 to N, then the changes in
the non-dominant machines can be approximated using a
zero-th order model by
𝑋 𝑄+1,𝑄+1 ⋯ 𝑋 𝑄+1,𝑁 ∆𝛿 𝑄+1
⋮ ⋱ ⋮ ⋮ =
𝑋 𝑁,𝑄+1 ⋯ 𝑋 𝑁,𝑁 ∆𝛿 𝑁
𝑄 𝑁+𝑛
𝑘=1 𝑋 𝑄+1,𝑘 ∆𝛿 𝑘 − 𝑘=𝑁+1 𝑋 𝑄+1,𝑘 ∆𝛿 𝑘
⋮ ….(31)
𝑄 𝑁+𝑛
𝑘=1 𝑋 𝑁,𝑘 ∆𝛿 𝑘 − 𝑘=𝑁+1 𝑋 𝑁,𝑘 ∆𝛿 𝑘
Where
Fig. 4. The 68 bus, 16 generator test system
𝜇 𝑖𝑗
𝑥 𝑖,𝑗 = ……………(32)
𝜇 𝑖𝑖
V. SELECTIVEFEEDBACKMEASUREMENTS And
BASEDON DOMINANT MACHINES 𝜇 𝑖𝑗 = −𝐸 𝑖 𝐸𝑗 𝑌𝑖𝑗 sin(𝛿 𝑖 − 𝛿𝑗 − 𝜑 𝑖𝑗 ) i≠j …..(33)
The control method proposed in the previous 𝑁+𝑛
𝜇 𝑖𝑖 = − 𝑘≠𝑖 𝐸 𝑖 𝐸𝑗 𝑌𝑖𝑗 sin(𝛿 𝑖 − 𝛿𝑗 − 𝜑 𝑖𝑗 ) i=j ……….(34)
section requires generator rotor frequencies to be
implemented. Although with recent advances in wide area
frequency measurement (FNET) it may be possible to Note than when only the dominant machines are
provide synchronized global measurements, it is still not selected for the control action, only the rows corresponding
feasible to assume that all generator rotor frequencies are to the dominant machines will be used thereby reducing
simultaneously available. However, it is reasonable to the order of the system. This is advantageous since the
assume that a subset of the measurements are available for pseudo-inverse required to solve the set of equations is
feedback and the remainder of the states can be estimated more nearly square providing better convergence.
based on the available measurements. The most probable
machines to obtain measurements from are those machines VI. EXAMPLE AND RESULTS
which dominate coherent groups.
There are numerous methods for calculating Although the control has been developed
coherent groups in the literature [15]–[18]. In [18], the using the classical generator model, the control approach
coherency identification method is based on modal will be validated using the full 10th order model which
analysis and Gaussian elimination with full pivoting on the includes an exciter/AVR, turbine, and governor dynamics.
selected eigenvectors of the system to find the reference The model is given in the Appendix. The proposed control
generators and their group members. is validated on the 68 bus, 16 generator New England/New
The selected eigenvectors are chosen based on the York test system shown in Fig. 4. The coherent groupings
lowest oscillatory modes of the system. Once the dominant corresponding to the five slowest modes are indicated by
machines are found, a reduced order system is computed the dashed lines in Fig. 4. The network data and coherent
which captures the ―slow‖ dynamics of the original system. groupings are the same as in [19]. The transmission tie
In this process, the remaining unmeasured states of the lines are shown with bold lines. The reference generators
system can be estimated based on the states which are for the five areas are G5, G13, G14, G15, and G16.
measured via singular perturbation [13]. Let the dominant
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5. International Journal of Modern Engineering Research (IJMER)
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TABLE I FACTS PARAMETERS that by definition, the shunt active power absorbed is
positive, thus during steady-state the STATCOM will
absorb active power and the figures indicate a positive
value. The shunt converter injects active power into the
system during the fault. Similar behavior is displayed by
Choosing the appropriate number of FACTS the STATCOMs as shown in Fig. 8. Fig. 9 shows the dc
controllers in the network is based on the number of link capacitor voltages. The UPFC and one of the
coherent areas. As a rule of thumb, it is best to match the STATCOMs experience a drop of approximately 5%
number of current injections with the number of modes. whereas the second STATCOM experiences a slight
For example, five current injections can be used to control increase in voltage. This is reasonable, since to damp
the interarea oscillations between five areas. In the 68 bus oscillations, it may be necessary to inject active power in
example, four current injections are used: one UPFC (two some areas and absorb active power in other areas.
injections) and two STATCOMS (one injection each). In
this paper, the UPFC is placed on line 1–2 with the shunt VII. CONCLUSIONS
converter on bus 2 and the STATCOMS have been placed A three stage nonlinear control scheme
on buses 47 and 49. The placements of the FACTS has been proposed for damping interarea oscillations using
controllers were heuristically chosen to be at buses at the multiple FACTS controllers. Any FACTS device that can
edge of the areas as might occur in practice. Several control its interface bu angle(s) with the power network
researchers have addressed the problem of optimal can utilize this control approach. The method uses the
placement of FACTS controllers. In [20], the authors generators’ frequencies as the feedback data for the
utilize modal sensitivity to determine placement of TCSCs. control. Using measurements from the dominant generators
Eigenvalue shift is used as a placement strategy for SVCs and estimating the rest of the states based on equivalent
in [21]. [22] focuses on the determination of the best bus reduced systems is shown to considerably reduce the
placement for SVCs to damp interarea oscillations. number of needed global measurements for control. Based
Another recent work addresses the use of modal on the simulation results, the proposed method shows
controllability indices specifically for FACTS placement promising results for wide-area control of power systems.
for oscillation damping [23]. There are several issues which need to be considered
The parameters of the FACTS controllers are however.
given in Table I. The per unit approach is the same as in There is a considerable computational burden for
[24] on a 100 MW, 100 kV base. the controller which requires fast processors for real-time
In the simulations, a solid three-phase fault is performance. However, good coherent groupings will
applied to bus 30 at 0.2 seconds and cleared at 0.3 seconds. lower the computation time by improving the estimation
The dynamic responses to this fault are shown for the process. Future work will also consider the effect of time
following cases: delays and communication noise in the measured states on
Case 1) proposed control, all measurements available; the control effectiveness. Sensitivity of the proposed
Case 2) proposed control, only dominant machine method to system uncertainties and topology changes will
measurements available; also be studied.
Case 3) linear control (taken from [25]).
Note that in Case 2), the estimation approach
proposed in Section V is used to obtain approximations to
the non-measured states.
Fig.5shows a subset of the generator speeds with
no FACTS controllers in the system compared to Case 1).
Not all responses are shown for the sake of brevity. The
selected generators are taken from four of the five coherent
areas (generator 15 is by itself in an area and is not shown).
Note that the generators go unstable as a result of the fault,
but the proposed control is able to stablize the system and
rapidly mitigate the oscillations.
Fig. 6 shows the active power injections of the
UPFC. The series injection is shown in the top figure and
the shunt injection is shown in the bottom figure. In this
figure, Case 2 (bold) is compared to Case 3 (thin). These
series active power injection for the proposed control is
very modest; therefore the rating ofthe series transformer
and converter do not need to be overly large. The shunt Fig. 5. Generator speeds for no FACTS controllers (bold)
active power is related to the series active power and Case 1 (thin).
𝑉2
−𝑃 𝑠𝑢𝑛𝑡 = 𝑃 𝑠𝑒𝑟𝑖𝑒𝑠 − 𝑑𝑐
𝑅 𝑑𝑐
………..(35)
Therefore 𝑃 𝑠𝑢𝑛𝑡 will be opposite in polarity
to 𝑃 𝑠𝑒𝑟𝑖𝑒𝑠 and will differ in magnitude by the losses in the
converter. Furthermore, during transients the dc link
capacitor will charge or discharge active power. Also note
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[2] B. C. Pal, ―Robust damping of interarea oscillations
with unified power flowcontroller,‖ Proc. Inst. Elect.
Eng., Gen. Transm. Distrib., vol. 149, no. 6, pp. 733–
738, Nov. 2002.
[3] B. Chaudhuri, B. C. Pal, A. Zolotas, I. Jaimoukha,
and T. Green, ―Mixed-sensitivity approach to � �
control of power system oscillations employing
multiple FACTS devices,‖ IEEE Trans. Power Syst.,
vol. 18, no. 3, pp. 1149–1156, Aug. 2004.
[4] M. M. Farsangi, Y. H. Song, and K. Y. Lee, ―Choice
of FACTS device control inputs for damping
interarea oscillations,‖ IEEE Trans. Power Syst., vol.
19, no. 2, pp. 1135–1143, May 2004.
[5] N. Tambey and M. L. Kothari, ―Damping of power
system oscillations with unified power flow
controller (UPFC),‖ Proc. Inst. Elect. Eng., Gen.,
Transm. Distrib., vol. 150, pp. 129–140, Mar. 2003.
[6] M. Ghandhari, G. Andersson, and I. A. Hiskens,
―Control Lyapunov functions for controllable series
devices,‖ IEEE Trans. Power Syst., vol. 16, no. 4, pp.
Fig. 6. UPFC injected active power: Series (top) and shunt
689–694, Nov. 2001.
(bottom); Case 2 (bold) and Case 3 (dashed).
[7] S. Robak, M. Januszewski, and D. D.
Rasolomampionona, ―Power system stability
enhancement using PSS and Lyapunov-based
controllers: A comparative study,‖ in Proc. IEEE
Power Tech Conf., Bologna, Italy, 2003, vol. 3, p. 6.
[8] C.-C. Chu and H.-C. Tsai, ―Application of
Lyapunov-based adaptive neural network UPFC
damping controllers for transient stability
enhancement,‖ presented at the IEEE Power Energy
Soc. General Meet., Pittsburgh, PA, Jul. 20–24, 2008.
[9] A. Bidadfar, M. Abedi, M. Karari, and C.-C. Chu,
―Power swings damping improvement by control of
UPFC and SMES based on direct Lyapunov method
application,‖ presented at the IEEE Power and
Energy Soc. General Meet., Pittsburgh, PA, Jul. 20–
24, 2008.
[10] M. Januszewski, J. Machowski, and J. W. Bialek,
Fig. 7. STATCOM active power injection: Case 2 (bold),
―Application of th direct Lyapunov method to
Case 3 (dashed).
improve damping of power swings by control of
UPFC,‖ Proc. Inst. Elect. Eng., Gen., Transm.
Distrib., vol. 151, pp. 252–260, Mar. 2004.
[11] Z. Zhong, C. Xu, B. J. Billian, L. Zhang, S. J. Tsai,
R. W. Conners, V. A. Centeno, A. G. Phadke, and Y.
Liu, ―Power system frequency monitoring
network (FNET) implementation,‖ IEEE Trans.
Power Syst., vol. 20, no. 4, pp. 1914–1921, Nov.
2005.
[12] L. Dong, M. L. Crow, Z. Yang, and S. Atcitty, ―A
reconfigurable FACTS system for university
laboratories,‖ IEEE Trans. Power Syst., vol. 19, no.
1, pp. 120–128, Feb. 2004.
[13] P. Sauer and M. A. Pai, Power System Dynamics and
Fig. 8. FACTS Vdc: Case 2 (bold) and Case 3 (dashed). Stability. Upper Saddle River, NJ: Prentice-Hall,
1998.
[14] W.-H. Chen, D. J. Balance, and P. J. Gawthrop,
REFERENCES ―Optimal control of nonlinear systems:Apredictive
[1] H. Wang, ―A unified model for the analysis of control approach,‖ Automatica, vol. 39, pp. 633–641,
FACTS devices in damping power system 2003.
oscillations—Part III: Unified power flow [15] J. H. Chow, R. Galarza, P. Accari, and W. W. Price,
controller,‖ IEEE Trans. Power Del., vol. 15, no. 3, ―Inertial and slow coherency aggregation algorithms
pp. 978–983, Jul. 2000. for power system dynamic model reduction,‖ IEEE
www.ijmer.com 4271 | Page
7. International Journal of Modern Engineering Research (IJMER)
www.ijmer.com Vol.2, Issue.6, Nov-Dec. 2012 pp-4266-4272 ISSN: 2249-6645
Trans. Power Syst., vol. 10, no. 2, pp. 680–685, May
1995.
[16] S. Geeves, ―A modal-coherency technique for
deriving dynamic equivalents,‖ IEEE Trans Power
Syst., vol. 3, no. 1, pp. 44–51, Feb. 1998.
[17] M. L. Ourari, L.-A. Dessaint, and V.-Q. Do,
―Dynamic equivalent modeling of large power M Praveen Kumar received B.Tech Degree in
Electrical & Electronics Engg. from JNT University, Hyderabad,
systems using structure preservation technique,‖ India. Presently he is with Annamacharya Institute of
IEEE Trans. Power Syst., vol. 21, no. 3, pp. 1284– Technology & Sciences, Rajampet, A.P,India, in Dept. of EEE
1295, Aug. 2006. and pursuing his M.Tech. His research interests includes power
[18] , J. H. Chow, Ed., Time-Scale Modeling of Dynamic systems, FACTS,
Networks With Applications to Power Systems.
Berlin, Germany: Springer-Verlag, 1982.
[19] G. Rogers, Power System Oscillations. Norwell, MA:
Kluwer, 2000.
[20] E. V. Larsen, J. J. Sanchez-Gasca, and J. H. Chow,
―Concepts for design of FACTS controllers to damp P.B Chennaiah received B.Tech Degree in
Electrical & Electronics Engg, from JNT University, Anantapur,
power swings,‖ IEEE Trans. Power Syst., vol. 10, no. India. M..Tech degree in electrical engineering from JNT
2, pp. 948–956, May 1995. University,Hyderabad. Presently he is with Annamacharya
[21] P. Pourbeik and M. J. Gibbard, ―Simultaneous Institute of Technology & Sciences, Rajampet, A.P,India, in
coordination of power system stabilizers and FACTS Dept. of EEE as an Associate professor. His research includes
device stabilizers in a multimachine power system optimization techniques in power systems, FACTS,
for enhancing dynamic performance,‖ IEEE Trans.
Power Syst., vol. 13, no. 2, pp. 473–479, May 1998.
[22] N. Martins and L. T. G. Lima, ―Determination of
suitable locations for power system stabilizers and
static VAR compensators for damping
electromechanical oscillations in large scale power
systes,‖ IEEE Trans. Power Syst., vol. 5, no. 4, pp.
1455–1469, Nov. 1990.
[23] B. K. Kumar, S. Singh, and S. Srivastava,
―Placement of FACTS controllers using modal
controllability indices to damp out power system
oscillations,‖ Proc. Inst. Eng. Technol., Gen.,
Transm., Distrib., vol. 1, no. 2, pp. 252–260, Mar.
2007.
[24] C. Schauder and H. Mehta, ―Vector analysis and
control of advanced static VAR compensators,‖ Proc.
Inst. Elect. Eng., C, vol. 140, no. 4, 1993.
[25] M. Zarghami and M. L. Crow, ―Discussion of
effective control of interarea oscillations by UPFCs,‖
presented at the 39th North American Power Symp.,
Las Cruces, NM, Oct. 2007.
www.ijmer.com 4272 | Page