State Estimation of Power System with Interline Power Flow ControllerIDES Editor
Now-a-days Flexible A.C. Transmission
System (FACTS) controllers are incorporated into the
power system network to control the power flow and
enhance system stability. Traditional state estimation
methods without integrating FACTS devices will not be
suitable for power systems embedded with FACTS
controller. Based on the conventional power system state
estimation model, a new method is proposed wherein an
IPFC based power injection model is incorporated in the
state estimation algorithm. Interline power flow controller
(IPFC) is one of the versatile FACTS device. The
proposed method is tested on Anderson and Fouad 9-bus
test system and the results are presented.
Power System State Estimation - A ReviewIDES Editor
The aim of this article is to provide a comprehensive
survey on power system state estimation techniques. The
algorithms used for finding the system states under both static
and dynamic state estimations are discussed in brief. The
authors are opinion that the scope of pursuing research in the
area of state estimation with PMU and SCADA measurements
is the state of the art and timely.
Voltage Regulators Placement in Unbalanced Radial Distribution Systems for Lo...paperpublications3
Abstract: The Automatic Voltage Regulators (AVRs) help to reduce energy loss and improve the power quality of electric utilities. This paper presents selection of optimal location and tap setting for voltage regulators in Unbalanced Radial Distribution Systems (URDS). Power loss index (PLI) is used for the selection of optimal location of voltage regulators which will first found at each branch except source bus and the bus that has the highest power loss index are picked as the best location for the voltage regulators placement. Particle swarm optimization (PSO), is used for selecting the tap position of voltage regulator in an unbalanced radial distribution system. This algorithm makes the initial selection and tap position setting of the voltage regulators to minimize power losses and provide a good voltage profile along the distribution network and then reduce the total cost to obtain the maximum net savings. The effectiveness of the proposed method is illustrated on a test system of IEEE 33 bus unbalanced radial distribution systems.
Keywords:Unbalanced Radial Distribution Systems (URDS), Load Flow, Power loss index(PLI),Particle swarm optimization(PSO), Voltage Regulator placement, Loss minimization, cost saving.
Locating Facts Devices in Optimized manner in Power System by Means of Sensit...IJERA Editor
This paper presents a new method to find the optimal location of facts devices by analyzing sensitivity . The optimal location and capability of Static Var Compensator (SVC) and Thyristor Controlled Series Capacitor (TCSC) in transmission line is investigated for enchasing the power transfer capability and stability of the system. The method firstly put all the buses in the order by voltage reactive power sensitivity and then chooses the optimal location and appropriate capability of the facts devices. It is simple in computation and suitable for large scale interconnection power grid. The results obtained are satisfying and will be useful for enhancing the power system reliability
Locating Facts Devices in Optimized manner in Power System by Means of Sensit...IJERA Editor
This paper presents a new method to find the optimal location of facts devices by analyzing sensitivity . The optimal location and capability of Static Var Compensator (SVC) and Thyristor Controlled Series Capacitor (TCSC) in transmission line is investigated for enchasing the power transfer capability and stability of the system. The method firstly put all the buses in the order by voltage reactive power sensitivity and then chooses the optimal location and appropriate capability of the facts devices. It is simple in computation and suitable for large scale interconnection power grid. The results obtained are satisfying and will be useful for enhancing the power system reliability
This work presents a study of the three-phase parallel active power filter and the various controllers used in its control. Moreover, in order to improve the quality of electrical energy, by making it conform to the new normative constraints, we have also been led to develop and apply advanced automation methods. In this framework, this paper reports of several regulatory structures : fuzzy logic, PWM, new space vector PWM (NSVPWM), space vector PWM (SVPWM), HYSTERESIS moreover, in order to produce a parallel active filter, a thorough study of experimental feasibility was carried out, taking into account the industrial constraints of the product both in its design and its application.
Total Harmonic Distortion of Dodecagonal Space Vector ModulationIJPEDS-IAES
Space vector modulation technique is one of the best PWM techniques which have been implemented to the Multilevel inverter circuit to get the purely sinusoidal cuurent. This is a important algorithm which is implemented in open wind induction motor. This type of I.M has great impact on Electric Drive system. SVM is nothing but the technique of switching algorithm. The Hexagonal space vector modulation has been implemented before, but elimination of higher order harmonics is not possible. Torque pulsation arises. Speed control of Induction motor was not smooth. So Dodecagonal (12) structure developed. A 12 side polygonal space vector structure is meant for eliminating (6n±1) harmonics in the phase current waveform throughout the modulating range. A high resolution of PWM technique is proposed involving multiple 12 sided polygonal (Dodecagonal) structure that can generate highly sinusoidal voltage at a reduced switching frequency. In this paper different values of frequencies have been taken for harmonic analysis. SVM method features a higher level of dc-bus voltage utilization compared to the conventional PWM.
State Estimation of Power System with Interline Power Flow ControllerIDES Editor
Now-a-days Flexible A.C. Transmission
System (FACTS) controllers are incorporated into the
power system network to control the power flow and
enhance system stability. Traditional state estimation
methods without integrating FACTS devices will not be
suitable for power systems embedded with FACTS
controller. Based on the conventional power system state
estimation model, a new method is proposed wherein an
IPFC based power injection model is incorporated in the
state estimation algorithm. Interline power flow controller
(IPFC) is one of the versatile FACTS device. The
proposed method is tested on Anderson and Fouad 9-bus
test system and the results are presented.
Power System State Estimation - A ReviewIDES Editor
The aim of this article is to provide a comprehensive
survey on power system state estimation techniques. The
algorithms used for finding the system states under both static
and dynamic state estimations are discussed in brief. The
authors are opinion that the scope of pursuing research in the
area of state estimation with PMU and SCADA measurements
is the state of the art and timely.
Voltage Regulators Placement in Unbalanced Radial Distribution Systems for Lo...paperpublications3
Abstract: The Automatic Voltage Regulators (AVRs) help to reduce energy loss and improve the power quality of electric utilities. This paper presents selection of optimal location and tap setting for voltage regulators in Unbalanced Radial Distribution Systems (URDS). Power loss index (PLI) is used for the selection of optimal location of voltage regulators which will first found at each branch except source bus and the bus that has the highest power loss index are picked as the best location for the voltage regulators placement. Particle swarm optimization (PSO), is used for selecting the tap position of voltage regulator in an unbalanced radial distribution system. This algorithm makes the initial selection and tap position setting of the voltage regulators to minimize power losses and provide a good voltage profile along the distribution network and then reduce the total cost to obtain the maximum net savings. The effectiveness of the proposed method is illustrated on a test system of IEEE 33 bus unbalanced radial distribution systems.
Keywords:Unbalanced Radial Distribution Systems (URDS), Load Flow, Power loss index(PLI),Particle swarm optimization(PSO), Voltage Regulator placement, Loss minimization, cost saving.
Locating Facts Devices in Optimized manner in Power System by Means of Sensit...IJERA Editor
This paper presents a new method to find the optimal location of facts devices by analyzing sensitivity . The optimal location and capability of Static Var Compensator (SVC) and Thyristor Controlled Series Capacitor (TCSC) in transmission line is investigated for enchasing the power transfer capability and stability of the system. The method firstly put all the buses in the order by voltage reactive power sensitivity and then chooses the optimal location and appropriate capability of the facts devices. It is simple in computation and suitable for large scale interconnection power grid. The results obtained are satisfying and will be useful for enhancing the power system reliability
Locating Facts Devices in Optimized manner in Power System by Means of Sensit...IJERA Editor
This paper presents a new method to find the optimal location of facts devices by analyzing sensitivity . The optimal location and capability of Static Var Compensator (SVC) and Thyristor Controlled Series Capacitor (TCSC) in transmission line is investigated for enchasing the power transfer capability and stability of the system. The method firstly put all the buses in the order by voltage reactive power sensitivity and then chooses the optimal location and appropriate capability of the facts devices. It is simple in computation and suitable for large scale interconnection power grid. The results obtained are satisfying and will be useful for enhancing the power system reliability
This work presents a study of the three-phase parallel active power filter and the various controllers used in its control. Moreover, in order to improve the quality of electrical energy, by making it conform to the new normative constraints, we have also been led to develop and apply advanced automation methods. In this framework, this paper reports of several regulatory structures : fuzzy logic, PWM, new space vector PWM (NSVPWM), space vector PWM (SVPWM), HYSTERESIS moreover, in order to produce a parallel active filter, a thorough study of experimental feasibility was carried out, taking into account the industrial constraints of the product both in its design and its application.
Total Harmonic Distortion of Dodecagonal Space Vector ModulationIJPEDS-IAES
Space vector modulation technique is one of the best PWM techniques which have been implemented to the Multilevel inverter circuit to get the purely sinusoidal cuurent. This is a important algorithm which is implemented in open wind induction motor. This type of I.M has great impact on Electric Drive system. SVM is nothing but the technique of switching algorithm. The Hexagonal space vector modulation has been implemented before, but elimination of higher order harmonics is not possible. Torque pulsation arises. Speed control of Induction motor was not smooth. So Dodecagonal (12) structure developed. A 12 side polygonal space vector structure is meant for eliminating (6n±1) harmonics in the phase current waveform throughout the modulating range. A high resolution of PWM technique is proposed involving multiple 12 sided polygonal (Dodecagonal) structure that can generate highly sinusoidal voltage at a reduced switching frequency. In this paper different values of frequencies have been taken for harmonic analysis. SVM method features a higher level of dc-bus voltage utilization compared to the conventional PWM.
Design and Performance Analysis of Genetic based PID-PSS with SVC in a Multi-...IDES Editor
Damping of power system oscillations with the help
of proposed optimal Proportional Integral Derivative Power
System Stabilizer (PID-PSS) and Static Var Compensator
(SVC)-based controllers are thoroughly investigated in this
paper. This study presents robust tuning of PID-PSS and
SVC-based controllers using Genetic Algorithms (GA) in
multi machine power systems by considering detailed model
of the generators (model 1.1). The effectiveness of FACTSbased
controllers in general and SVC-based controller in
particular depends upon their proper location. Modal
controllability and observability are used to locate SVC–based
controller. The performance of the proposed controllers is
compared with conventional lead-lag power system stabilizer
(CPSS) and demonstrated on 10 machines, 39 bus New England
test system. Simulation studies show that the proposed genetic
based PID-PSS with SVC based controller provides better
performance.
Line Losses in the 14-Bus Power System Network using UPFCIDES Editor
Controlling power flow in modern power systems
can be made more flexible by the use of recent developments
in power electronic and computing control technology. The
Unified Power Flow Controller (UPFC) is a Flexible AC
transmission system (FACTS) device that can control all the
three system variables namely line reactance, magnitude and
phase angle difference of voltage across the line. The UPFC
provides a promising means to control power flow in modern
power systems. Essentially the performance depends on proper
control setting achievable through a power flow analysis
program. This paper presents a reliable method to meet the
requirements by developing a Newton-Raphson based load
flow calculation through which control settings of UPFC can
be determined for the pre-specified power flow between the
lines. The proposed method keeps Newton-Raphson Load Flow
(NRLF) algorithm intact and needs (little modification in the
Jacobian matrix). A MATLAB program has been developed to
calculate the control settings of UPFC and the power flow
between the lines after the load flow is converged. Case studies
have been performed on IEEE 5-bus system and 14-bus system
to show that the proposed method is effective. These studies
indicate that the method maintains the basic NRLF properties
such as fast computational speed, high degree of accuracy and
good convergence rate.
Open switch fault diagnosis in three phase inverter using diagnostic variable...eSAT Journals
The reliability of power electronics system such as three phase inverter is important in various applications. Different types of faults occur in it, which may influence the operation of system. Such faults require unexpected maintenance, which increases the cost of manufacturing. Therefore fault diagnosis of such devices plays vital role in industry. One possible fault that occurs in inverter is an open switch fault. This paper provides a new technique based on diagnostic variable which detects single as well as multiple open switch fault in three phase inverter. In this method, diagnostic variables are used to detect faulty phase. Along with these diagnostic variables, an average current of three phase inverter is used for the detection of single as well as multiple faulty switches. Key Words: Power electronics, open switch fault, diagnostic variables.
International Journal of Engineering and Science Invention (IJESI) is an international journal intended for professionals and researchers in all fields of computer science and electronics. IJESI publishes research articles and reviews within the whole field Engineering Science and Technology, new teaching methods, assessment, validation and the impact of new technologies and it will continue to provide information on the latest trends and developments in this ever-expanding subject. The publications of papers are selected through double peer reviewed to ensure originality, relevance, and readability. The articles published in our journal can be accessed online.
PID controller using rapid control prototyping techniquesIJECEIAES
To analyze the performance of the PID controller in a buck type converter implemented in real time. We begin by designing a continuous controller using the analytical method for calculating PIDs. Pulse width modulation is then used and bifurcation diagrams analyzed to reveal some problems of switching and sampling time. The model converter is then implemented with a PID controller in dSPACE. The experimental results provide detailed requirements of sampling frequency and switching speed, and show the performance of the PID controller. Converters are used in power generation solar systems and conmuted power sources for feed telecommunication devices, smart grids, and other applications.
This paper presents a nonlinear Integral backstepping control approach based on field oriented control technique, applied to a Double Star Induction Machine ‘DSIM’ feed by two power voltage sources. We present this technique of integral backstepping by using reduced and complete Model of DSIM. The objective is to improve the robustness of machine under internal parameter variation with nonlinear Integral backstepping control. The robustness test results obtained by simulation prove the effectiveness of control with using complete model of DSIM.
THD Minimisation for Phase Voltage of Multilevel Inverters Using Genetic Algo...theijes
The International Journal of Engineering & Science is aimed at providing a platform for researchers, engineers, scientists, or educators to publish their original research results, to exchange new ideas, to disseminate information in innovative designs, engineering experiences and technological skills. It is also the Journal's objective to promote engineering and technology education. All papers submitted to the Journal will be blind peer-reviewed. Only original articles will be published.
Artificial Intelligence Technique based Reactive Power Planning Incorporating...IDES Editor
Reactive Power Planning is a major concern in the
operation and control of power systems This paper compares
the effectiveness of Evolutionary Programming (EP) and
New Improved Differential Evolution (NIMDE) to solve
Reactive Power Planning (RPP) problem incorporating
FACTS Controllers like Static VAR Compensator (SVC),
Thyristor Controlled Series Capacitor (TCSC) and Unified
power flow controller (UPFC) considering voltage stability.
With help of Fast Voltage Stability Index (FVSI), the critical
lines and buses are identified to install the FACTS controllers.
The optimal settings of the control variables of the generator
voltages,transformer tap settings and allocation and parameter
settings of the SVC,TCSC,UPFC are considered for reactive
power planning. The test and Validation of the proposed
algorithm are conducted on IEEE 30–bus system and 72-bus
Indian system.Simulation results shows that the UPFC gives
better results than SVC and TCSC and the FACTS controllers
reduce the system losses.
Simulation, bifurcation, and stability analysis of a SEPIC converter control...IJECEIAES
This article presents some results of SEPIC converter dynamics when controlled by a center pulse width modulator controller (CPWM). The duty cycle is calculated using the ZAD (Zero Average Dynamics) technique. Results obtained using this technique show a great variety of non-linear phenomena such as bifurcations and chaos, as parameters associated with the switching surface. These phenomena have been studied in the present paper in numerical form. Simulations were done in MATLAB.
Comparative analysis of improved high performance direct power control of thr...eSAT Journals
Abstract
Direct Power Control with switching table control produces irregular ripples and variable switching frequency. In the improved DPC of PWM rectifiers using fractional control period of the active voltage vector and the rest period for the null vector not only makes it line side inductance independent of the circuit and is very simple to implement due to the duty cycle concept. By simulation it is identified that the level of distortion as well as regulation of the DC link voltage with control of power factor improves the overall performance of the drive. The improved Direct Power Control (DPC) PWM methodology is comprehensively analyzed and studied for three phase rectifiers and compared with the classical DPC with PLL. The MATLAB simulations shows the effectiveness in obtaining unity power factor and constant dc link voltage control. The power ripples are considerably reduced and input sinusoidal grid currents are obtained.
Keywords— Direct power control, instantaneous active and reactive power, pulse width modulation, duty cycle, dc link control, unity power factor
Optimal Placement of DG for Loss Reduction and Voltage Sag Mitigation in Radi...IDES Editor
This paper presents the need to operate the power
system economically and with optimum levels of voltages has
further led to an increase in interest in Distributed
Generation. In order to reduce the power losses and to improve
the voltage in the distribution system, distributed generators
(DGs) are connected to load bus. To reduce the total power
losses in the system, the most important process is to identify
the proper location for fixing and sizing of DGs. It presents a
new methodology using a new population based meta heuristic
approach namely Artificial Bee Colony algorithm(ABC) for
the placement of Distributed Generators(DG) in the radial
distribution systems to reduce the real power losses and to
improve the voltage profile, voltage sag mitigation. The power
loss reduction is important factor for utility companies because
it is directly proportional to the company benefits in a
competitive electricity market, while reaching the better power
quality standards is too important as it has vital effect on
customer orientation. In this paper an ABC algorithm is
developed to gain these goals all together. In order to evaluate
sag mitigation capability of the proposed algorithm, voltage
in voltage sensitive buses is investigated. An existing 20KV
network has been chosen as test network and results are
compared with the proposed method in the radial distribution
system.
OPTIMAL TORQUE RIPPLE CONTROL OF ASYNCHRONOUS DRIVE USING INTELLIGENT CONTROL...elelijjournal
The dynamic performance of an asynchronous machine when operated with cascaded Voltage Source Inverter using Space Vector Modulation (SVM) technique is presented in this paper. A classical model of Induction Motor Drive based on Direct Torque Control (DTC) method is considered which displays
appreciable run-time operation with very simple hysteresis control scheme. Direct control of the torque and flux variables is achieved by choosing suitable inverter voltage space vector from a lookup table. Under varying torque conditions the performance of the drive system is verified using MATLAB/Simulink software tool. The ripple content in the torque parameter is significant when traditional PI controller and Fuzzy approach are configured in the proposed system. Finally, by replacing the PI-Fuzzy controller with Hybrid Controller the torque ripple minimization can be achieved during no-load and loaded conditions.
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.
Design and Performance Analysis of Genetic based PID-PSS with SVC in a Multi-...IDES Editor
Damping of power system oscillations with the help
of proposed optimal Proportional Integral Derivative Power
System Stabilizer (PID-PSS) and Static Var Compensator
(SVC)-based controllers are thoroughly investigated in this
paper. This study presents robust tuning of PID-PSS and
SVC-based controllers using Genetic Algorithms (GA) in
multi machine power systems by considering detailed model
of the generators (model 1.1). The effectiveness of FACTSbased
controllers in general and SVC-based controller in
particular depends upon their proper location. Modal
controllability and observability are used to locate SVC–based
controller. The performance of the proposed controllers is
compared with conventional lead-lag power system stabilizer
(CPSS) and demonstrated on 10 machines, 39 bus New England
test system. Simulation studies show that the proposed genetic
based PID-PSS with SVC based controller provides better
performance.
Line Losses in the 14-Bus Power System Network using UPFCIDES Editor
Controlling power flow in modern power systems
can be made more flexible by the use of recent developments
in power electronic and computing control technology. The
Unified Power Flow Controller (UPFC) is a Flexible AC
transmission system (FACTS) device that can control all the
three system variables namely line reactance, magnitude and
phase angle difference of voltage across the line. The UPFC
provides a promising means to control power flow in modern
power systems. Essentially the performance depends on proper
control setting achievable through a power flow analysis
program. This paper presents a reliable method to meet the
requirements by developing a Newton-Raphson based load
flow calculation through which control settings of UPFC can
be determined for the pre-specified power flow between the
lines. The proposed method keeps Newton-Raphson Load Flow
(NRLF) algorithm intact and needs (little modification in the
Jacobian matrix). A MATLAB program has been developed to
calculate the control settings of UPFC and the power flow
between the lines after the load flow is converged. Case studies
have been performed on IEEE 5-bus system and 14-bus system
to show that the proposed method is effective. These studies
indicate that the method maintains the basic NRLF properties
such as fast computational speed, high degree of accuracy and
good convergence rate.
Open switch fault diagnosis in three phase inverter using diagnostic variable...eSAT Journals
The reliability of power electronics system such as three phase inverter is important in various applications. Different types of faults occur in it, which may influence the operation of system. Such faults require unexpected maintenance, which increases the cost of manufacturing. Therefore fault diagnosis of such devices plays vital role in industry. One possible fault that occurs in inverter is an open switch fault. This paper provides a new technique based on diagnostic variable which detects single as well as multiple open switch fault in three phase inverter. In this method, diagnostic variables are used to detect faulty phase. Along with these diagnostic variables, an average current of three phase inverter is used for the detection of single as well as multiple faulty switches. Key Words: Power electronics, open switch fault, diagnostic variables.
International Journal of Engineering and Science Invention (IJESI) is an international journal intended for professionals and researchers in all fields of computer science and electronics. IJESI publishes research articles and reviews within the whole field Engineering Science and Technology, new teaching methods, assessment, validation and the impact of new technologies and it will continue to provide information on the latest trends and developments in this ever-expanding subject. The publications of papers are selected through double peer reviewed to ensure originality, relevance, and readability. The articles published in our journal can be accessed online.
PID controller using rapid control prototyping techniquesIJECEIAES
To analyze the performance of the PID controller in a buck type converter implemented in real time. We begin by designing a continuous controller using the analytical method for calculating PIDs. Pulse width modulation is then used and bifurcation diagrams analyzed to reveal some problems of switching and sampling time. The model converter is then implemented with a PID controller in dSPACE. The experimental results provide detailed requirements of sampling frequency and switching speed, and show the performance of the PID controller. Converters are used in power generation solar systems and conmuted power sources for feed telecommunication devices, smart grids, and other applications.
This paper presents a nonlinear Integral backstepping control approach based on field oriented control technique, applied to a Double Star Induction Machine ‘DSIM’ feed by two power voltage sources. We present this technique of integral backstepping by using reduced and complete Model of DSIM. The objective is to improve the robustness of machine under internal parameter variation with nonlinear Integral backstepping control. The robustness test results obtained by simulation prove the effectiveness of control with using complete model of DSIM.
THD Minimisation for Phase Voltage of Multilevel Inverters Using Genetic Algo...theijes
The International Journal of Engineering & Science is aimed at providing a platform for researchers, engineers, scientists, or educators to publish their original research results, to exchange new ideas, to disseminate information in innovative designs, engineering experiences and technological skills. It is also the Journal's objective to promote engineering and technology education. All papers submitted to the Journal will be blind peer-reviewed. Only original articles will be published.
Artificial Intelligence Technique based Reactive Power Planning Incorporating...IDES Editor
Reactive Power Planning is a major concern in the
operation and control of power systems This paper compares
the effectiveness of Evolutionary Programming (EP) and
New Improved Differential Evolution (NIMDE) to solve
Reactive Power Planning (RPP) problem incorporating
FACTS Controllers like Static VAR Compensator (SVC),
Thyristor Controlled Series Capacitor (TCSC) and Unified
power flow controller (UPFC) considering voltage stability.
With help of Fast Voltage Stability Index (FVSI), the critical
lines and buses are identified to install the FACTS controllers.
The optimal settings of the control variables of the generator
voltages,transformer tap settings and allocation and parameter
settings of the SVC,TCSC,UPFC are considered for reactive
power planning. The test and Validation of the proposed
algorithm are conducted on IEEE 30–bus system and 72-bus
Indian system.Simulation results shows that the UPFC gives
better results than SVC and TCSC and the FACTS controllers
reduce the system losses.
Simulation, bifurcation, and stability analysis of a SEPIC converter control...IJECEIAES
This article presents some results of SEPIC converter dynamics when controlled by a center pulse width modulator controller (CPWM). The duty cycle is calculated using the ZAD (Zero Average Dynamics) technique. Results obtained using this technique show a great variety of non-linear phenomena such as bifurcations and chaos, as parameters associated with the switching surface. These phenomena have been studied in the present paper in numerical form. Simulations were done in MATLAB.
Comparative analysis of improved high performance direct power control of thr...eSAT Journals
Abstract
Direct Power Control with switching table control produces irregular ripples and variable switching frequency. In the improved DPC of PWM rectifiers using fractional control period of the active voltage vector and the rest period for the null vector not only makes it line side inductance independent of the circuit and is very simple to implement due to the duty cycle concept. By simulation it is identified that the level of distortion as well as regulation of the DC link voltage with control of power factor improves the overall performance of the drive. The improved Direct Power Control (DPC) PWM methodology is comprehensively analyzed and studied for three phase rectifiers and compared with the classical DPC with PLL. The MATLAB simulations shows the effectiveness in obtaining unity power factor and constant dc link voltage control. The power ripples are considerably reduced and input sinusoidal grid currents are obtained.
Keywords— Direct power control, instantaneous active and reactive power, pulse width modulation, duty cycle, dc link control, unity power factor
Optimal Placement of DG for Loss Reduction and Voltage Sag Mitigation in Radi...IDES Editor
This paper presents the need to operate the power
system economically and with optimum levels of voltages has
further led to an increase in interest in Distributed
Generation. In order to reduce the power losses and to improve
the voltage in the distribution system, distributed generators
(DGs) are connected to load bus. To reduce the total power
losses in the system, the most important process is to identify
the proper location for fixing and sizing of DGs. It presents a
new methodology using a new population based meta heuristic
approach namely Artificial Bee Colony algorithm(ABC) for
the placement of Distributed Generators(DG) in the radial
distribution systems to reduce the real power losses and to
improve the voltage profile, voltage sag mitigation. The power
loss reduction is important factor for utility companies because
it is directly proportional to the company benefits in a
competitive electricity market, while reaching the better power
quality standards is too important as it has vital effect on
customer orientation. In this paper an ABC algorithm is
developed to gain these goals all together. In order to evaluate
sag mitigation capability of the proposed algorithm, voltage
in voltage sensitive buses is investigated. An existing 20KV
network has been chosen as test network and results are
compared with the proposed method in the radial distribution
system.
OPTIMAL TORQUE RIPPLE CONTROL OF ASYNCHRONOUS DRIVE USING INTELLIGENT CONTROL...elelijjournal
The dynamic performance of an asynchronous machine when operated with cascaded Voltage Source Inverter using Space Vector Modulation (SVM) technique is presented in this paper. A classical model of Induction Motor Drive based on Direct Torque Control (DTC) method is considered which displays
appreciable run-time operation with very simple hysteresis control scheme. Direct control of the torque and flux variables is achieved by choosing suitable inverter voltage space vector from a lookup table. Under varying torque conditions the performance of the drive system is verified using MATLAB/Simulink software tool. The ripple content in the torque parameter is significant when traditional PI controller and Fuzzy approach are configured in the proposed system. Finally, by replacing the PI-Fuzzy controller with Hybrid Controller the torque ripple minimization can be achieved during no-load and loaded conditions.
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.
What is islanding ?
Consider the power network as shown in fig.1
Now if we disconnect the line AB from the infinite transmission grid there will be an isolated region . The D1, D2 are power sources (eg : inverter , solar power cells ). The power generated in this region is fed to the island only.
We see that there no longer is any control over the island voltage at the bus X . Also there is no mechanism here for control of frequency.
This state is referred to as islanding.
This presentation is intended for giving an introduction to Genetic Algorithm. Using an example, it explains the different concepts used in Genetic Algorithm. If you are new to GA or want to refresh concepts , then it is a good resource for you.
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Power System State Estimation Using Weighted Least Squares (WLS) and Regulari...IJERA Editor
In this paper, a new formulation for power system state estimation is proposed. The formulation is based on
regularized least squares method which uses the principle of Thikonov’s regularization to overcome the
limitations of conventional state estimation methods. In this approach, the mathematical unfeasibility which
results from the lack of measurements in case of ill-posed problems is eliminated. This paper also deals with
comparison of conventional method of state estimation and proposed formulation. A test procedure based n the
variance of the estimated linearized power flows is proposed to identify the observable islands of the system.
The obtained results are compared with the results obtained by conventional WLS method
International Journal of Engineering Research and Development (IJERD)IJERD Editor
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A Novel Distribution System Power Flow Algorithm using Forward Backward Matri...iosrjce
IOSR Journal of Electrical and Electronics Engineering(IOSR-JEEE) is a double blind peer reviewed International Journal that provides rapid publication (within a month) of articles in all areas of electrical and electronics engineering and its applications. The journal welcomes publications of high quality papers on theoretical developments and practical applications in electrical and electronics engineering. Original research papers, state-of-the-art reviews, and high quality technical notes are invited for publications.
Permanent Fault Location in Distribution System Using Phasor Measurement Unit...IJECEIAES
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Indigenized remote control interface card suitable for MAFI system CCR equipment. Compatible for IDM8000 CCR. Backplane mounted serial and TCP/Ethernet communication module for CCR remote access. IDM 8000 CCR remote control on serial and TCP protocol.
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AKS UNIVERSITY Satna Final Year Project By OM Hardaha.pdf
interconnected powersystem
1. Power System State Estimation And Bad Data Analysis Using
WLS Method And Weighted Least Trimmed Sum Of Absolute
Deviation
-:Prepared by:-
Divyangkumar R Soni.
(160410707008)
2. PAPERS
PAPER 1.
Power System State Estimation and Bad Data Analysis Using
Weighted Least Square Method
1.T P Vishnu
2.Vidya Vishwan
3.Vipian A M
[2015 IEEE International Conference on Power, Instrumentation, Control and
Computing (PICC) ]
PAPER 2.
Power System State Estimation Using Weighted Least Trimmed
Sum of Absolute Deviation
1. B. Vedik
2.Ashwani Kumar Chandel
[IEEE INDICON 2015]
2
3. PAPER 1.
Power System State Estimation(PSSE) and Bad Data
Analysis Using Weighted Least Square Method
OUTLINE :-
1. Abstract
2. Introduction
3. State Estimation
4. Component Modelling
5. Newton Raphsons Load Flow Analysis
6. Weighted Least Square State Estimatios
7. Bad Data Detection And Identification
8. Bad Data Detection
9. Bad Data Identification
10.Program And Output
11.References
3
4. ABSTRACT
This paper explains the concept of Weighted Least Square static state
estimation.
Static state estimation is performed on the data made available through the
SCADA system.
In this paper this data is obtained through Newton Raphson Load flow
analysis.
Power flow, power injections and voltage magnitudes are the various
measurements taken from load flow analysis as the measurements for state
estimation.
Weighted least square method estimates the state of the power system
based on the weight given to each measurement.
A state estimator should have the ability to detect and identify the presence
of a bad data.
4
5. ABSTRACT
If a bad data is present among the measurements, then the estimated state
variables will vary from the actual state variables.
In this paper bad data detection is performed using Chi Squared test and
bad data identification is performed using largest normalized residual
method.
Weighted least square algorithm is applied on an IEEE 14 bus.
5
6. INTRODUCTION
State estimation is an important part of power system security analysis.
Power system operations can be controlled from the load dispatch center
on obtaining various informations about the current state of the power
system.
These information include various meter readings,
1. Transformer Tap Position,
2. Circuit Breaker Position
3. Network Topology
Transmission of these information to the SCADA center is not always
reliable.
Errors can be caused by improper connection of transducer
loss of data while transmitting or due to the presence of faulty meters.
So,if these wrong data is used for Contingency Analysis in power system
it will give false alarm signal and can even cause unnecessary tripping of
power system elements.
6
7. INTRODUCTION
PSSE is simply do using SCADA system.
Using Phasor Measurement Units (PMU) increase the accuracy of the
state estimation technique.
PMU based state estimation algorithm to obtain a more robust result .
Recent techniques of SE using Multi Sensor data fusion theory can
give a better result.
the network topology and voltage phasor, all the measurements can be
estimated.
So the least number of variables that can define a power system are
voltage magnitude and voltage angle.
Hence they are referred as the static state of the system.
7
8. INTRODUCTION
Based on the operating condition power system can remain in any of the
five operating states :
8
Preventive
control
Emergency
control
Resynchronization
Load pick up
Fig .1 operating state
9. STATE ESTIMATION
The state estimators typically include the following functions:
9
Topology processor
Observability analysis
State estimation solution
Bad data processing
Error processing
10. COMPONENT MODELLING
For running the state estimation algorithm power system network topology
has to be known.
Transmission lines are represented by a two-port π network whose
impedance and shunt reactances are the positive sequence component
impedances .
A transmission line with a positive sequence series impedance of R+jX
and total line charging susceptance of j2B, will be modelled by the
equivalent circuit shown in Fig 2
10
11. The effect of a tap changing transformer on a Ybus is shown in Fig 3.
11
Ybus can be obtained by writing the nodal equations at each node.
12. NEWTON RAPHSONS LOAD FLOW
ANALYSIS
The true measurements for the PSSE is found out using
Newton Raphsons Load flow analysis .
NR load flow analysis
12
Calculate Ybus
Take voltage magnitude and voltage
angle using bus deta
Caculate P and Q injections
Select Specified value of (Pi,Qi) which is usually the
power injection at each bus
Calculated Change in power injection ΔPi,Δqi &
Jacobian matrix is calculated
Using the Jacobian matrix the
change in state variable is calculated
process is
repeated.
13. WEIGHTED LEAST SQUARE STATE
ESTIMATION
1. Measurement Function :
The state vector is given by following equation :
Each equation corresponding to the measured variable can be
represented. Equations of active and reactive power injection and power
flows are given by Eqn 4 – 7.
13
14. 2. Gain Matrix G(x):
WLS State Estimation involves an
iterative solution of the objective function
which is given by :
WLS equations are given by:
14
15. BAD DATA DETECTION AND
IDENTIFICATION
Functions of a state estimator is :-
1. Detect measurement errors.
2. Identify and eliminate them if possible .
Errors in measurements are due to various reasons:-
1. Accuracy of meters.
2. Telecommunication networks lead to random errors.
3. The meters have biases, drifts or wrong connections.
4. Telecommunication system failures.
Negative voltage measurements or large difference in current entering and
leaving the bus are possible large bad data.
15
16. BAD DATA DETECTION
A. Chi Squared Test
Consider a set of n independent random variables X1,X2,X3...Xn where
each Xp is distributed according to the Standard Normal distribution :
Xp N(0,1)∼
A new random variable Y can be defined as :
will have chi squared distribution with N degrees of freedom
i.e. Y χ2 N∼
16
17. 17
X
ChisquareB. Use of χ2 distribution for bad data detection
Probability of finding x is given by
the area under the curve in the χ2
probability density function(pdf).
Once we set the probability as say
0.1 then we can calculate the
threshold x as in eqn 18.
C. χ2 Test for Detecting Bad Data
Solve the WLS
estimation problem
and compute the
objective function:
From the χ2 distribution
table find the value
corresponding to probability
p and degrees of freedom
(m−n).
If there is a
bad data
then
18. BAD DATA IDENTIFICATION
Identification can be accomplished by further processing of the residuals.
Largest Normalized Residual Test can identify the presence of a bad data
and has following steps:
1. Calculate the residual covariance matrix Ω using following steps.
2. Hat Matrix K = H ×G^1 ×HT ×R^1 .
3. Residual Sensitivity Matrix S = I −K.
4. Residual Covariance Matrix Ω=S ×R.
18
20. PAPER 2.
Power System State Estimation Using Weighted Least
Trimmed Sum of Absolute Deviation
OUTLINE :-
1. Abstract
2. Introduction
3. State Estimation Problem Formulation
4. Orthogonal Crossover Based Differential Evolution Algorithm
5. Implementation Of Psse Using Oxde
6. Results And Discussion
7. Conclusions
8. References
20
21. ABSTRACT
This paper suggests the application of one such robust estimator known as
weighted least trimmed sum of absolute (WLTA) deviation estimator to
PSSE.
The main principle of WLTA estimator is to optimize the weighted sum of
the absolute residuals of rank υ.
In the present work, the PSSE problem is solved as an optimization
problem using orthogonal crossover based differential evolution
algorithm.
The proposed method has been demonstrated on IEEE 14-bus and IEEE
30-bus systems under normal and bad data conditions
21
22. INTRODUCTION
SE problem is generally solved iteratively using Gauss-Newton based
weighted least squares (WLS) estimator due to its high efficiency .
In order to make WLS estimator robust it is generally followed by largest
normalized residual test to recognize and remove the bad measurements.
The main contribution of the paper is to introduce a new statistical robust
estimator known as weighted least trimmed sum of absolute deviation
estimator to PSSE.
The state estimation problem has been solved as an optimization problem
using orthogonal crossover based differential evolution (OXDE)
algorithm.
The efficacy and robustness of the proposed approach is tested on :-
IEEE 14-bus and IEEE 30-bus systems under both normal and bad data
conditions.
22
23. STATE ESTIMATION PROBLEM
FORMULATION
The mathematical model for SE that relates measurements to the state
variables is expressed by the following equation :
Z=h(x) + e
where,
Z= signifies the measurement vector of order (m*1)
x =indicates the state vector of order ( n*1)
e= represents measurements errors of order (m*1),
(these errors are normally assumed as Gaussian distributed with zero
mean and standard deviation σ.)
In the present work, the above SE problem is solved using:-
the weighted least trimmed sum of absolute deviation estimator.
23
24. The WLTA estimator minimizes the sum of the υ th order residuals that is
given as follows :-
Where,
ri is indicate the i th residual .
wi is indicate i th measurement error .
Depending upon the number of bad data measurements the value of υ can
be increased to increase the accuracy and efficiency of the SE.
24
25. ORTHOGONAL CROSSOVER BASED
DIFFERENTIAL EVOLUTION ALGORITHM
A. CLASSICAL DIFFERENTIAL EVOLUTION ALGORITHM
After initialization, Differential evolution (DE) performs difference
vector mutation and crossover operation to generate new vectors.
1. Mutation operation :
2.Crossover operation:
3. Selection:
25
26. B. ORTHOGONAL CROSSOVER BASED DIFFERENTIAL EVOLUTION
the convergence characteristics of the conventional DE depend mainly on
two important parameters:
1. The tuning of control parameters
2. The selection of donor and trial vectors generation strategies
Selected randomly by generating a number uniformly in between 0 and 1
for mutant vector that undergoes quantization orthogonal crossover
operation :
where,
(0,1) rand indicates the uniformly distributed random number generated
in-between (0,1) .
26
27. IMPLEMENTATION OF PSSE USING OXDE
27
Obtain true measurement by performing
load flow analysis
Read system data and initialize the control parameter
Perform offline synchronization of
measurement
Perform PSSE using orthogonal
crossover differential evolution
final report
28. RESULTS AND DISCUSSION
the power system are estimated using the conventional and PMU
measurements placed optimally across the power system network.
28
Table .1 The problem statistics are summarized
Table .2 Control parameter settings for both the test systems
29. The comparison of the proposed method with WLS method is performed
using the performance indices such as ,
1. Average absolute voltage error (AAVE)
2. Average absolute angle error (AAAE)
of the estimated state variables of the estimated measurements.
A. NORMAL OPERATING CONDITION
29
Table .3 Performance indices of different systems under normal
condition
30. B. BAD DATA CONDITION
30
Table .4 Performance indices of different systems
by considering single bad data measurement
Table .5 Performance indices of
different systems by considering two
bad data measurement
Table .6 Performance indices of
different systems by considering three
bad data measurement
Table .7 Performance indices of
different systems by considering four
bad data measurement
31. CONCLUSIONS
A new robust weighted least trimmed sum of absolute deviation estimator
is introduced to PSSE.
The robustness of the proposed method in comparison with WLS algorithm
has been validated by applying it to IEEE 14-bus and IEEE 30-bus test
systems under normal and bad data conditions.
The PSSE problem has been solved as an optimization problem using
OXDE technique
31
32. REFERENCES
[A] Hui Xue, Quing-quan Jia ‘A Dynamic state estimation method with PMU
and SCADA Measurement for Power System’, The 8th International
Power Engineering Conference, pp. 848-853, Dec 2007.
[B] F.C.Schweppe, and J.Wildes,‘Power system static-state estimation, part 1:
exact model’, IEEE trans. Power app. Syst., vol. 3, no. 4, pp. 120–135 Jan.
1970.
[1] A. K. Al-Othman and M. R. Irving, “Robust state estimator based on
maximum constraints satisfaction of uncertain measurements,”
Measurement, Vol. 40, No. 3, pp. 347–359, Apr. 2007.
[2] D. M. Hawkins and D. Olive, “Applications and algorithms for least
trimmed sum of absolute deviations regression,” Computational Statistics
& Data Analysis, Vol. 32, No. 2, pp. 119-134, Dec. 1999.
32