The Need for Enhanced Power System Modelling Techniques & Simulation Tools Power System Operation
The Need for Enhanced Power System Modelling Techniques & Simulation Tools The Need for Enhanced Power System Modelling Techniques The Need for Enhanced Power System Modelling Techniques & Simulation Tools The Need for Enhanced Power System Modelling Techniques & Simulation Tools & Simulation Tools
MODELLING AND IMPLEMENTATION OF AN IMPROVED DSVM SCHEME FOR PMSM DTCpaperpublications3
Abstract: A very widely used drive strategy for PMSM is the field oriented control (FOC), which was proposed in 1971 for induction motors (IMs). However, the FOC scheme is quite complex due to the reference frame transformation and its high dependence upon the motor parameters and speed. To mitigate these problems, a new control strategy for the torque control of induction motor was developed by Takahashi known as the direct torque control (DTC) and by Depenbrock as the direct self control (DSC). The basic direct torque control (DTC) scheme may cause undesired torque, flux and current ripples because of the small number of applicable voltage vectors. The control system should be able to generate any voltage vector, implying the use of space vector modulation (SVM) which complicates the control scheme. The discrete space vector modulation (DSVM) method was proposed for DTC to overcome this problem which replaces the simple switching table by several switching tables, to apply a combination of three voltage vectors in the same sampling period. In this paper, after a brief review of the primary concept of DSVM DTC technique, a new scheme of DSVM DTC for PMSM is proposed with a new set of switching tables taking into account the motor speed and the absolute values of torque and flux feedback errors. In one fixed sampling time interval, three vectors are applied to the motor including the two null vectors. Comparisons of the basic DTC and the improved DSVM DTC schemes are made based on the system performance and switching loss. For this purpose the DSVM technique uses prefixed time intervals within a sampling cycle to synthesize a higher number of voltage vectors than the basic DTC scheme. A set of switching table is carried out to minimize the torque error. An optimal vector selector is developed to reduce the switching loss and make the system more stable. The sampling period does not need to be doubled in order to achieve a mean switching frequency practically equal to that of the basic DTC scheme. For a comparable performance, the switching loss of the proposed scheme is less than that of the basic DTC method. The vector application sequence is investigated and an optimal algorithm is developed to reduce the switching loss and torque ripple. Simulation and experiments on the improved DSVM DTC are carried out and compared with those on the basic DTC scheme.
In this paper a novel control technique for switching-frequency-modulated switch-mode power converters (SMPC) operating in discontinuous conduction mode is proposed. The use of the technique leads to significant reduction in peak-to-peak output voltage and peak currents increased due to straightforward application of switching frequency modulation (SFM). The technique is based on hybrid modulation scheme in which both switching frequency and duty ratio are modulated simultaneously by the same modulation signal. Theoretical analysis and experimental verification of the proposed technique are presented in details. Both computer simulations and experiments show that switching-frequency-modulated SMPC with the proposed control technique in comparison to SMPC without SFM has appreaciably lower conducted electromagnetic emissions, at the cost of slightly increased peak-to-peak output voltage and peak currents.
Transient Monitoring Function based Fault Classifier for Relaying Applications IJECEIAES
This paper proposes Transient monitoring function (TMF) based fault classification approach for transmission line protection. The classifier provides accurate results under various system conditions involving fault resistance, inception angle, location and load angle. The transient component during fault is measured by TMF and appropriate logics applied for fault classification. Simulation studies using MATLAB ® /SIMULINK ™ are carried out for a 400 kV, 50 Hz power system with variable system conditions. Results show that the proposed classifier has high classification accuracy. The method developed has been compared with a fault classification technique based on Discrete Wavelet Transform (DWT). The proposed technique can be implemented for real time protection schemes employing distance relaying.
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 Need for Enhanced Power System Modelling Techniques & Simulation Tools Power System Operation
The Need for Enhanced Power System Modelling Techniques & Simulation Tools The Need for Enhanced Power System Modelling Techniques The Need for Enhanced Power System Modelling Techniques & Simulation Tools The Need for Enhanced Power System Modelling Techniques & Simulation Tools & Simulation Tools
MODELLING AND IMPLEMENTATION OF AN IMPROVED DSVM SCHEME FOR PMSM DTCpaperpublications3
Abstract: A very widely used drive strategy for PMSM is the field oriented control (FOC), which was proposed in 1971 for induction motors (IMs). However, the FOC scheme is quite complex due to the reference frame transformation and its high dependence upon the motor parameters and speed. To mitigate these problems, a new control strategy for the torque control of induction motor was developed by Takahashi known as the direct torque control (DTC) and by Depenbrock as the direct self control (DSC). The basic direct torque control (DTC) scheme may cause undesired torque, flux and current ripples because of the small number of applicable voltage vectors. The control system should be able to generate any voltage vector, implying the use of space vector modulation (SVM) which complicates the control scheme. The discrete space vector modulation (DSVM) method was proposed for DTC to overcome this problem which replaces the simple switching table by several switching tables, to apply a combination of three voltage vectors in the same sampling period. In this paper, after a brief review of the primary concept of DSVM DTC technique, a new scheme of DSVM DTC for PMSM is proposed with a new set of switching tables taking into account the motor speed and the absolute values of torque and flux feedback errors. In one fixed sampling time interval, three vectors are applied to the motor including the two null vectors. Comparisons of the basic DTC and the improved DSVM DTC schemes are made based on the system performance and switching loss. For this purpose the DSVM technique uses prefixed time intervals within a sampling cycle to synthesize a higher number of voltage vectors than the basic DTC scheme. A set of switching table is carried out to minimize the torque error. An optimal vector selector is developed to reduce the switching loss and make the system more stable. The sampling period does not need to be doubled in order to achieve a mean switching frequency practically equal to that of the basic DTC scheme. For a comparable performance, the switching loss of the proposed scheme is less than that of the basic DTC method. The vector application sequence is investigated and an optimal algorithm is developed to reduce the switching loss and torque ripple. Simulation and experiments on the improved DSVM DTC are carried out and compared with those on the basic DTC scheme.
In this paper a novel control technique for switching-frequency-modulated switch-mode power converters (SMPC) operating in discontinuous conduction mode is proposed. The use of the technique leads to significant reduction in peak-to-peak output voltage and peak currents increased due to straightforward application of switching frequency modulation (SFM). The technique is based on hybrid modulation scheme in which both switching frequency and duty ratio are modulated simultaneously by the same modulation signal. Theoretical analysis and experimental verification of the proposed technique are presented in details. Both computer simulations and experiments show that switching-frequency-modulated SMPC with the proposed control technique in comparison to SMPC without SFM has appreaciably lower conducted electromagnetic emissions, at the cost of slightly increased peak-to-peak output voltage and peak currents.
Transient Monitoring Function based Fault Classifier for Relaying Applications IJECEIAES
This paper proposes Transient monitoring function (TMF) based fault classification approach for transmission line protection. The classifier provides accurate results under various system conditions involving fault resistance, inception angle, location and load angle. The transient component during fault is measured by TMF and appropriate logics applied for fault classification. Simulation studies using MATLAB ® /SIMULINK ™ are carried out for a 400 kV, 50 Hz power system with variable system conditions. Results show that the proposed classifier has high classification accuracy. The method developed has been compared with a fault classification technique based on Discrete Wavelet Transform (DWT). The proposed technique can be implemented for real time protection schemes employing distance relaying.
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.
Comparative Analysis of PWM Techniques for Three Level Diode Clamped Voltage ...IAES-IJPEDS
Multilevel inverters are increasingly being used in high-power medium voltage industrial drive applications due to their superior performance compared to conventional two-level inverters. Thre are a number of Pulse width modulation (PWM) techniques applied in recent years. The most widely applied PWM techniques are Sine Pulse Width Modulation (SPWM) and Space Vector Pulse Width Modulation (SVPWM). SPWM is the most simple modulation technique that can realize easily in analog circuit. However, it has some drawbacks such as higher total harmonic distortion (THD), lower effective DC utilization and lower switching frequency. Space vector pulse width modulation (SVPWM) is widely used because of their easier digital realization and better DC bus utilization and lower THD. The complexity is due to the difficulty in determining the reference vector location, on times calculation, and switching states selection. This paper presents a simple SVPWM algorithm for diode clamped three level inverters based on standard two-level SVPWM which can easily determine the location of reference vector, calculate the on-times, the selection of switching states. Three level diode clamped inverter (3LDCI) using space vector modulation technique has been modeled and simulated using MATLAB/SIMULINK and Origin 6.1 with a passive R-L load that can be extended to any level. Simulation results are presented to verify the proposed SVPWM control in terms of THD. The results arecompared with conventional sinusoidal pulse width modulation (SPWM) where SVPWM shows better performance than SPWM in terms of THD.
Wide Area Fault Location for Power Transmission Network using Reactance Based...Muhd Hafizi Idris
Download here: https://www.researchgate.net/publication/332441499_Wide_Area_Fault_Location_for_Power_Transmission_Network_using_Reactance_Based_Method?_sg=Tkk3ur2Kc3XGh3JHwtJdPM3IdJJx_K42N3Zu9kX_ECutHW5j91ExIMtrJFOui4E-RikSYmuYR0uZWEEVHoSaDTPZuRvC29V6GzZ5g9BS.GnmzKNF1XN22czjk5npta57bMn8D2KxxwQsAMEPlK7abE5qGykkxj8CgUcnYHlzpKEZST1ujqv7avTquOi7Aug
With the advancements in smart grid, communication technology, intelligent electronic device and substation automation, wide area applications for monitoring, protection, control and fault location becoming focused nowadays and improved from time to time. This research focuses on using wide area synchrophasor measurements for fault location in transmission network which acts as a backup to conventional fault location method. Simple reactance based methods together with a developed rules system are used to locate the possible affected line and its fault location. Using the developed rules and algorithm, fault location impedance will be compared at each synchrophasor bus connected lines for different fault types, then between connected lines and finally between synchrophasors buses. Faults at various locations with different fault resistances have been simulated and the results prove that the developed method can be used to locate the fault point and can be used as a backup to main fault location method. Future works also discussed how the method can be improved to get the best and accurate fault location results.
Improvise 3-Level DTC of Induction Machine using Constant Switching Frequency...IJPEDS-IAES
This paper presents the advantage of using optimal PI parameter tuning strategy of constant switching method in the three phase Direct torque control (DTC) scheme. The DTC system is known to offer fast decoupled control of torque and flux via a simple control structure. Nevertheless, DTC system has two major drawbacks, which are the variable inverter switching frequency and high torque output ripple. The major factorthat contributes to these problems the usage of hysteresis based comparators to control the output torque. The implementation of PI based constant switching method in DTC able to solve these problems while retaining the simple control structure of conventional DTC. The combination usage of 3-level CHMI in this system can further minimize the output torque ripple by providing greater number of vectors. This paper presents detail explanation and calculationof optimal PI parameter tuning strategyconsecutively to enhance the performance of 3-level DTC system. In order to validate the feasibility, the proposed method compared with convention DTC system via simulation and experiment results.
A Refined Space Vector PWM Signal Generation for Multilevel InvertersIDES Editor
A refined space vector modulation scheme for
multilevel inverters, using only the instantaneous sampled
reference signals is presented in this paper. The proposed
space vector pulse width modulation technique does not require
the sector information and look-up tables to select the
appropriate switching vectors. The inverter leg switching times
are directly obtained from the instantaneous sampled
reference signal amplitudes and centers the switching times
for the middle space vectors in a sampling time interval, as in
the case of conventional space vector pulse width modulation.
The simulation results are presented to a five-level inverter
system for dual-fed induction motor drive. The dual-fed
structure is realized by opening the neutral-point of the
conventional squirrel cage induction motor. The five-level
inversion is obtained by feeding the dual-fed induction motor
with four-level inverter from one end and two-level inverter
from the other end.
Signal-Energy Based Fault Classification of Unbalanced Network using S-Transf...idescitation
This paper presents a technique for diagnosis of the type of fault and the faulty
phase on overhead transmission line. The proposed method is based on the multiresolution
S-Transform and Parseval’s theorem. S-Transform is used to produce instantaneous
frequency vectors of the voltage signals of the three phases, and then the energies of these
vectors, based on the Parseval’s theorem, are utilized as inputs to a Probabilistic Neural
Network (PNN). The power system network considered in this study is three phase
Transmission line with unbalanced loading simulated in the PowerSim Toolbox of
MATLAB. The fault conditions are simulated by the variation of fault location, fault
resistance, fault inception angle. The training is conducted by programming in MATLAB.
The robustness of the proposed scheme is investigated by synthetically polluting the
simulated voltage signals with White Gaussian Noise. The suggested method has produced
fast and accurate results. Estimation of fault location is intended to be conducted in future.
Index Terms—
Fast svm based 3 phase cascaded five level invertereSAT Journals
Abstract Introduction of nearest three vector algorithm is a major achievement in the area of space vector technology. Complexity and severe computations are still the drawbacks of SVM methods mainly for multilevel inverter applications. A fast SVM technique is introduced in this project which allows the calculation of switch time duration and the efficient determination of switching times based on the two level inverter scheme. SVM modulating waves are generated based on the two level system and then this modulating waves are compared with required number of carrier signals in order to generate the switching pulses for the inverter. Four triangular carrier signals are needed for a five level system in order to generate the switching pulses. Coordinates of the nearest three voltage vectors is not needed, so the complexity of the SVM technique can be reduced and it is the major advantage of the proposed technique compared with conventional SVM techniques used for multilevel inverters. A three phase five level cascaded H bridge topology is used here to verify the effectiveness of the proposed technique. MATLAB simulation and hardware implementation of the proposed system is done. From the analysis of both simulation and hardware it is clear that proposed SVM technique have more fundamental output and less THD than sinusoidal PWM technique. Key Words: Cascaded H bridge, Multilevel, Modulating wave, Space vector
The peer-reviewed International Journal of Engineering Inventions (IJEI) is started with a mission to encourage contribution to research in Science and Technology. Encourage and motivate researchers in challenging areas of Sciences and Technology.
Experimental simulation analysis for single phase transformer testsjournalBEEI
Transformer is one of main components in electrical power system which role to increase or reduce voltage. Characteristics of transformer would be vital to ensure the voltage is fully transferred. A single-phase transformer is a type of power transformer that utilizes single-phase alternating current, meaning the transformer relies on a voltage cycle that operates in a unified time phase. This article describes a workflow executed with Mat lab simulation and practical measurements for single-phase power transformer, no-load, short-circuit test and load test are achieved in this work. The test procedures are implemented on areal transformer (terco-type) which has a specification (1 KVA, 220/110 V, 50 Hz). Finally, the simulation results are appeared a proximately seminar from the practical results. The results indicated that the the technique and manner which presented in the current study can be depended as a miniproject in electrical technology mater for undergraduate studies.
Monitoring and Control of Power System Oscillations using FACTS/HVDC and Wide...Power System Operation
Power oscillations are a growing concern among power system operators worldwide. Traditionally, the
main countermeasure against dangerous power oscillations has been the installation of power system
stabilizers (PSS). Essentially, the potential for inter-area power oscillations depends on the strength of
the tie lines between different areas and the load on the ties. From a European perspective, with the
anticipated integration of remote renewable energy sources such as offshore wind power from the
North-sea region and solar power from southern Europe or Africa, we can expect the average
transmission distances to grow and consequently also tie line flows. Unless tie lines are also reinforced
we expect more oscillation events in the European grid in the future.
From an operational point of view, it is of high priority to be able to estimate the damping of
oscillatory modes reliably in real-time in order to take appropriate and timely measures in case
damping becomes poor. Recent developments in wide-area phasor monitoring have resulted in a new
power oscillation monitoring algorithm that uses multiple measurements from different locations in
the grid. An equivalent system model of the power grid is estimated in real-time and based on this
model, the damping and frequency as well the activity of oscillatory modes can be determined from
ambient process variations. As basis for this, a wide-area measurement system (WAMS) can provide
time synchronized signals from phasor measurement units (PMUs) that can measure voltage, current
and frequency with adequate accuracy and resolution in time. This paper shows results from pilot
operation of the new application at swissgrid, including recordings from an actual and representative
event in the continental ENTSO-E interconnected power system. This example demonstrates the
performance of the new application as well as provides information about the oscillatory modes
present in the continental ENTSO-E system today.
International Refereed Journal of Engineering and Science (IRJES)irjes
International Refereed Journal of Engineering and Science (IRJES) is a leading international journal for publication of new ideas, the state of the art research results and fundamental advances in all aspects of Engineering and Science. IRJES is a open access, peer reviewed international journal with a primary objective to provide the academic community and industry for the submission of half of original research and applications
Comparative Analysis of PWM Techniques for Three Level Diode Clamped Voltage ...IAES-IJPEDS
Multilevel inverters are increasingly being used in high-power medium voltage industrial drive applications due to their superior performance compared to conventional two-level inverters. Thre are a number of Pulse width modulation (PWM) techniques applied in recent years. The most widely applied PWM techniques are Sine Pulse Width Modulation (SPWM) and Space Vector Pulse Width Modulation (SVPWM). SPWM is the most simple modulation technique that can realize easily in analog circuit. However, it has some drawbacks such as higher total harmonic distortion (THD), lower effective DC utilization and lower switching frequency. Space vector pulse width modulation (SVPWM) is widely used because of their easier digital realization and better DC bus utilization and lower THD. The complexity is due to the difficulty in determining the reference vector location, on times calculation, and switching states selection. This paper presents a simple SVPWM algorithm for diode clamped three level inverters based on standard two-level SVPWM which can easily determine the location of reference vector, calculate the on-times, the selection of switching states. Three level diode clamped inverter (3LDCI) using space vector modulation technique has been modeled and simulated using MATLAB/SIMULINK and Origin 6.1 with a passive R-L load that can be extended to any level. Simulation results are presented to verify the proposed SVPWM control in terms of THD. The results arecompared with conventional sinusoidal pulse width modulation (SPWM) where SVPWM shows better performance than SPWM in terms of THD.
Wide Area Fault Location for Power Transmission Network using Reactance Based...Muhd Hafizi Idris
Download here: https://www.researchgate.net/publication/332441499_Wide_Area_Fault_Location_for_Power_Transmission_Network_using_Reactance_Based_Method?_sg=Tkk3ur2Kc3XGh3JHwtJdPM3IdJJx_K42N3Zu9kX_ECutHW5j91ExIMtrJFOui4E-RikSYmuYR0uZWEEVHoSaDTPZuRvC29V6GzZ5g9BS.GnmzKNF1XN22czjk5npta57bMn8D2KxxwQsAMEPlK7abE5qGykkxj8CgUcnYHlzpKEZST1ujqv7avTquOi7Aug
With the advancements in smart grid, communication technology, intelligent electronic device and substation automation, wide area applications for monitoring, protection, control and fault location becoming focused nowadays and improved from time to time. This research focuses on using wide area synchrophasor measurements for fault location in transmission network which acts as a backup to conventional fault location method. Simple reactance based methods together with a developed rules system are used to locate the possible affected line and its fault location. Using the developed rules and algorithm, fault location impedance will be compared at each synchrophasor bus connected lines for different fault types, then between connected lines and finally between synchrophasors buses. Faults at various locations with different fault resistances have been simulated and the results prove that the developed method can be used to locate the fault point and can be used as a backup to main fault location method. Future works also discussed how the method can be improved to get the best and accurate fault location results.
Improvise 3-Level DTC of Induction Machine using Constant Switching Frequency...IJPEDS-IAES
This paper presents the advantage of using optimal PI parameter tuning strategy of constant switching method in the three phase Direct torque control (DTC) scheme. The DTC system is known to offer fast decoupled control of torque and flux via a simple control structure. Nevertheless, DTC system has two major drawbacks, which are the variable inverter switching frequency and high torque output ripple. The major factorthat contributes to these problems the usage of hysteresis based comparators to control the output torque. The implementation of PI based constant switching method in DTC able to solve these problems while retaining the simple control structure of conventional DTC. The combination usage of 3-level CHMI in this system can further minimize the output torque ripple by providing greater number of vectors. This paper presents detail explanation and calculationof optimal PI parameter tuning strategyconsecutively to enhance the performance of 3-level DTC system. In order to validate the feasibility, the proposed method compared with convention DTC system via simulation and experiment results.
A Refined Space Vector PWM Signal Generation for Multilevel InvertersIDES Editor
A refined space vector modulation scheme for
multilevel inverters, using only the instantaneous sampled
reference signals is presented in this paper. The proposed
space vector pulse width modulation technique does not require
the sector information and look-up tables to select the
appropriate switching vectors. The inverter leg switching times
are directly obtained from the instantaneous sampled
reference signal amplitudes and centers the switching times
for the middle space vectors in a sampling time interval, as in
the case of conventional space vector pulse width modulation.
The simulation results are presented to a five-level inverter
system for dual-fed induction motor drive. The dual-fed
structure is realized by opening the neutral-point of the
conventional squirrel cage induction motor. The five-level
inversion is obtained by feeding the dual-fed induction motor
with four-level inverter from one end and two-level inverter
from the other end.
Signal-Energy Based Fault Classification of Unbalanced Network using S-Transf...idescitation
This paper presents a technique for diagnosis of the type of fault and the faulty
phase on overhead transmission line. The proposed method is based on the multiresolution
S-Transform and Parseval’s theorem. S-Transform is used to produce instantaneous
frequency vectors of the voltage signals of the three phases, and then the energies of these
vectors, based on the Parseval’s theorem, are utilized as inputs to a Probabilistic Neural
Network (PNN). The power system network considered in this study is three phase
Transmission line with unbalanced loading simulated in the PowerSim Toolbox of
MATLAB. The fault conditions are simulated by the variation of fault location, fault
resistance, fault inception angle. The training is conducted by programming in MATLAB.
The robustness of the proposed scheme is investigated by synthetically polluting the
simulated voltage signals with White Gaussian Noise. The suggested method has produced
fast and accurate results. Estimation of fault location is intended to be conducted in future.
Index Terms—
Fast svm based 3 phase cascaded five level invertereSAT Journals
Abstract Introduction of nearest three vector algorithm is a major achievement in the area of space vector technology. Complexity and severe computations are still the drawbacks of SVM methods mainly for multilevel inverter applications. A fast SVM technique is introduced in this project which allows the calculation of switch time duration and the efficient determination of switching times based on the two level inverter scheme. SVM modulating waves are generated based on the two level system and then this modulating waves are compared with required number of carrier signals in order to generate the switching pulses for the inverter. Four triangular carrier signals are needed for a five level system in order to generate the switching pulses. Coordinates of the nearest three voltage vectors is not needed, so the complexity of the SVM technique can be reduced and it is the major advantage of the proposed technique compared with conventional SVM techniques used for multilevel inverters. A three phase five level cascaded H bridge topology is used here to verify the effectiveness of the proposed technique. MATLAB simulation and hardware implementation of the proposed system is done. From the analysis of both simulation and hardware it is clear that proposed SVM technique have more fundamental output and less THD than sinusoidal PWM technique. Key Words: Cascaded H bridge, Multilevel, Modulating wave, Space vector
The peer-reviewed International Journal of Engineering Inventions (IJEI) is started with a mission to encourage contribution to research in Science and Technology. Encourage and motivate researchers in challenging areas of Sciences and Technology.
Experimental simulation analysis for single phase transformer testsjournalBEEI
Transformer is one of main components in electrical power system which role to increase or reduce voltage. Characteristics of transformer would be vital to ensure the voltage is fully transferred. A single-phase transformer is a type of power transformer that utilizes single-phase alternating current, meaning the transformer relies on a voltage cycle that operates in a unified time phase. This article describes a workflow executed with Mat lab simulation and practical measurements for single-phase power transformer, no-load, short-circuit test and load test are achieved in this work. The test procedures are implemented on areal transformer (terco-type) which has a specification (1 KVA, 220/110 V, 50 Hz). Finally, the simulation results are appeared a proximately seminar from the practical results. The results indicated that the the technique and manner which presented in the current study can be depended as a miniproject in electrical technology mater for undergraduate studies.
Monitoring and Control of Power System Oscillations using FACTS/HVDC and Wide...Power System Operation
Power oscillations are a growing concern among power system operators worldwide. Traditionally, the
main countermeasure against dangerous power oscillations has been the installation of power system
stabilizers (PSS). Essentially, the potential for inter-area power oscillations depends on the strength of
the tie lines between different areas and the load on the ties. From a European perspective, with the
anticipated integration of remote renewable energy sources such as offshore wind power from the
North-sea region and solar power from southern Europe or Africa, we can expect the average
transmission distances to grow and consequently also tie line flows. Unless tie lines are also reinforced
we expect more oscillation events in the European grid in the future.
From an operational point of view, it is of high priority to be able to estimate the damping of
oscillatory modes reliably in real-time in order to take appropriate and timely measures in case
damping becomes poor. Recent developments in wide-area phasor monitoring have resulted in a new
power oscillation monitoring algorithm that uses multiple measurements from different locations in
the grid. An equivalent system model of the power grid is estimated in real-time and based on this
model, the damping and frequency as well the activity of oscillatory modes can be determined from
ambient process variations. As basis for this, a wide-area measurement system (WAMS) can provide
time synchronized signals from phasor measurement units (PMUs) that can measure voltage, current
and frequency with adequate accuracy and resolution in time. This paper shows results from pilot
operation of the new application at swissgrid, including recordings from an actual and representative
event in the continental ENTSO-E interconnected power system. This example demonstrates the
performance of the new application as well as provides information about the oscillatory modes
present in the continental ENTSO-E system today.
International Refereed Journal of Engineering and Science (IRJES)irjes
International Refereed Journal of Engineering and Science (IRJES) is a leading international journal for publication of new ideas, the state of the art research results and fundamental advances in all aspects of Engineering and Science. IRJES is a open access, peer reviewed international journal with a primary objective to provide the academic community and industry for the submission of half of original research and applications
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.
Simulation Investigation of SPWM, THIPWM and SVPWM Techniques for Three Phase...IJPEDS-IAES
Pulse width modulation (PWM) technique is one of the vital issues for power electronic circuit control. A number of Pulse width modulation (PWM) techniques are increasingly applied in many new industrial applications that require superior performance. The most widely applied PWM technique for three-phase voltage source inverters are Sine Pulse Width Modulation (SPWM), Third Harmonic Injection Pulse Width Modulation (THIPWM) and Space Vector Pulse Width Modulation (SVPWM). SPWM is the most simple modulation technique that can realize easily in analog circuit. However, it has some drawbacks such as higher total harmonic distortion (THD), lower switching frequency and not capable in over modulation region. THIPWM and SVPWM both provide better THD compared to SPWM. SVPWM shows lower THD in over modulation region and in high frequency application compared to THIPWM. These three techniques are discussed, analyzed and compared in terms of modulation index, switching frequency and inverter input voltage in this paper. The modeling and simulation for all PWM techniques have been done by using MATLAB/SIMULINK and Origin 6.1. From the simulation results, SVPWM shows the best performance and meet IEEE 519 standard of current harmonics level.
A Fault Detection and Classification Method for SC Transmission Line Using Ph...paperpublications3
Abstract: In this paper, fault detection and classification for Series Compensated Line (SCL) using phasor measurement unit is presented. The algorithm presented in this paper uses the PMU synchronized measurements and not depends on the data to be provided by the electricity utility. The compensated line parameters and Thevenin’s equivalent (TE) of the system at SCL terminals are calculated online, using three independent sets of pre-fault phasor measurements. The accuracy of fault location is performed with respect to fault location/position, types of fault, fault angle. The accuracy of the algorithm is simulated in MATLAB for 9-bus transmission system.
A comparative study for detection and measurement of voltage disturbance in o...IJERA Editor
Voltage disturbance is the most important power quality problem faced by many industrial customers. It includes voltage sag, swell, spikes and harmonics. Real time detection of these voltage disturbances posed various problems. This paper compares the various methods of detection of voltage sag and swells in real time on the basis of detection time, magnitude, effect of windowing and effect of sampling frequencies. The RMS, Peak, Fourier transform and Missing Voltage algorithm are introduced and discussed in them for real time implementation. Comparative analysis reveals that quantification of voltage sag and swell is possible using these measurements. The main focus is given on to these points and all the voltage sag and swell detection technique tested online with the help of advantech card data acquisition. The voltage sag and swell events are generated by using practical experimentation in laboratory.
Shunt Faults Detection on Transmission Line by Waveletpaperpublications3
Abstract: Transmission line fault detection is a very important task because major portion of power system fault occurring in transmission system. This paper represents a fast and reliable method of transmission line shunt fault detection. MATLAB Simulink use for modeled an IEEE 9-bus test power system for case study of various faults. In proposed work Daubechies wavelet is applied for decomposition of fault transients. The application of wavelet analysis helps in accurate classification of the various fault patterns. Wavelet entropy measure based on wavelet analysis is able to observe the unsteady signals and complexity of the system at time-frequency plane.
The result shows that the proposed method is capable to detect all the shunt faults.
A Tactical Chaos based PWM Technique for Distortion Restraint and Power Spect...IJPEDS-IAES
The pulse width modulated voltage source inverters (PWM-VSI) dominate in the modern industrial environment. The conventional PWM methods are designed to have higher fundamental voltage, easy filtering and reduced total harmonic distortion (THD). There are number of clustered harmonics around the multiples of switching frequency in the output of conventional sinusoidal pulse width modulation (SPWM) and space vector pulse width modulation (SVPWM) inverters. This is due to their fixed switching frequency while the variable switching frequency makes the filtering very complex. Random carrier PWM (RCPWM) methods are the host of PWM methods, which use randomized carrier frequency and result in a harmonic profile with well distributed harmonic power (no harmonic possesses significant magnitude and hence no filtering is required). This paper proposes a chaos-based PWM (CPWM) strategy, which utilizes a chaotically changing switching frequency to spread the harmonics continuously to a wideband and to reduce the peak harmonics to a great extent. This can be an effective way to suppress the current harmonics and torque ripple in induction motor drives. The proposed CPWM scheme is simulated using MATLAB / SIMULINK software and implemented in three phase voltage source inverter (VSI) using field programmable gate array (FPGA).
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.
Voltage variations identification using Gabor Transform and rule-based classi...IJECEIAES
This paper presents a comparatively contemporary easy to use technique for the identification and classification of voltage variations. The technique was established based on the Gabor Transform and the rule-based classification method. The technique was tested by using mathematical model of Power Quality (PQ) disturbances based on the IEEE Std 519-2009. The PQ disturbances focused were the voltage variations, which included voltage sag, swell and interruption. A total of 80 signals were simulated from the mathematical model in MATLAB and used in this study. The signals were analyzed by using Gabor Transform and the signal pattern, timefrequency representation (TFR) and root-mean-square voltage graph were presented in this paper. The features of the analysis were extracted, and rules were implemented in rule-based classification to identify and classify the voltage variation accordingly. The results showed that this method is easy to be used and has good accuracy in classifying the voltage variation.
WAVELET- FUZZY BASED MULTI TERMINAL TRANSMISSION SYSTEM PROTECTION SCHEME IN ...Wireilla
In This Paper, A New Protection Scheme In The Areas Of Accurate Fault Detection, Classification And Location Estimation For Multi Terminal Transmission System Compensated With Statcom Is Proposed. The Fault Indices Of All The Phases At All The Terminals Are Obtained By Analyzing The Detail Coefficients Of Current Signals Through Bior 1.5 Mother Wavelet. The Complete Digital Simulation Of A Transmission System With Statcom Is Performed Using Matlab /Simulink For Fault Detection, Classification, And Faulty Terminal Identification With Variations In Fault Distance And Fault Inception Angle For All Types Of Faults And Fuzzy Inference System Is Used To Estimate The Fault Location. The Protection Scheme Yielded Accurate Results Within Half Cycle And Show That The Above Scheme Is Suitable For Multi Terminal Transmission System With And Without Statcom Compensation.
A Novel Method for Prevention of Bandwidth Distributed Denial of Service AttacksIJERD Editor
Distributed Denial of Service (DDoS) Attacks became a massive threat to the Internet. Traditional
Architecture of internet is vulnerable to the attacks like DDoS. Attacker primarily acquire his army of Zombies,
then that army will be instructed by the Attacker that when to start an attack and on whom the attack should be
done. In this paper, different techniques which are used to perform DDoS Attacks, Tools that were used to
perform Attacks and Countermeasures in order to detect the attackers and eliminate the Bandwidth Distributed
Denial of Service attacks (B-DDoS) are reviewed. DDoS Attacks were done by using various Flooding
techniques which are used in DDoS attack.
The main purpose of this paper is to design an architecture which can reduce the Bandwidth
Distributed Denial of service Attack and make the victim site or server available for the normal users by
eliminating the zombie machines. Our Primary focus of this paper is to dispute how normal machines are
turning into zombies (Bots), how attack is been initiated, DDoS attack procedure and how an organization can
save their server from being a DDoS victim. In order to present this we implemented a simulated environment
with Cisco switches, Routers, Firewall, some virtual machines and some Attack tools to display a real DDoS
attack. By using Time scheduling, Resource Limiting, System log, Access Control List and some Modular
policy Framework we stopped the attack and identified the Attacker (Bot) machines
Hearing loss is one of the most common human impairments. It is estimated that by year 2015 more
than 700 million people will suffer mild deafness. Most can be helped by hearing aid devices depending on the
severity of their hearing loss. This paper describes the implementation and characterization details of a dual
channel transmitter front end (TFE) for digital hearing aid (DHA) applications that use novel micro
electromechanical- systems (MEMS) audio transducers and ultra-low power-scalable analog-to-digital
converters (ADCs), which enable a very-low form factor, energy-efficient implementation for next-generation
DHA. The contribution of the design is the implementation of the dual channel MEMS microphones and powerscalable
ADC system.
Influence of tensile behaviour of slab on the structural Behaviour of shear c...IJERD Editor
-A composite beam is composed of a steel beam and a slab connected by means of shear connectors
like studs installed on the top flange of the steel beam to form a structure behaving monolithically. This study
analyzes the effects of the tensile behavior of the slab on the structural behavior of the shear connection like slip
stiffness and maximum shear force in composite beams subjected to hogging moment. The results show that the
shear studs located in the crack-concentration zones due to large hogging moments sustain significantly smaller
shear force and slip stiffness than the other zones. Moreover, the reduction of the slip stiffness in the shear
connection appears also to be closely related to the change in the tensile strain of rebar according to the increase
of the load. Further experimental and analytical studies shall be conducted considering variables such as the
reinforcement ratio and the arrangement of shear connectors to achieve efficient design of the shear connection
in composite beams subjected to hogging moment.
Gold prospecting using Remote Sensing ‘A case study of Sudan’IJERD Editor
Gold has been extracted from northeast Africa for more than 5000 years, and this may be the first
place where the metal was extracted. The Arabian-Nubian Shield (ANS) is an exposure of Precambrian
crystalline rocks on the flanks of the Red Sea. The crystalline rocks are mostly Neoproterozoic in age. ANS
includes the nations of Israel, Jordan. Egypt, Saudi Arabia, Sudan, Eritrea, Ethiopia, Yemen, and Somalia.
Arabian Nubian Shield Consists of juvenile continental crest that formed between 900 550 Ma, when intra
oceanic arc welded together along ophiolite decorated arc. Primary Au mineralization probably developed in
association with the growth of intra oceanic arc and evolution of back arc. Multiple episodes of deformation
have obscured the primary metallogenic setting, but at least some of the deposits preserve evidence that they
originate as sea floor massive sulphide deposits.
The Red Sea Hills Region is a vast span of rugged, harsh and inhospitable sector of the Earth with
inimical moon-like terrain, nevertheless since ancient times it is famed to be an abode of gold and was a major
source of wealth for the Pharaohs of ancient Egypt. The Pharaohs old workings have been periodically
rediscovered through time. Recent endeavours by the Geological Research Authority of Sudan led to the
discovery of a score of occurrences with gold and massive sulphide mineralizations. In the nineties of the
previous century the Geological Research Authority of Sudan (GRAS) in cooperation with BRGM utilized
satellite data of Landsat TM using spectral ratio technique to map possible mineralized zones in the Red Sea
Hills of Sudan. The outcome of the study mapped a gossan type gold mineralization. Band ratio technique was
applied to Arbaat area and a signature of alteration zone was detected. The alteration zones are commonly
associated with mineralization. The alteration zones are commonly associated with mineralization. A filed check
confirmed the existence of stock work of gold bearing quartz in the alteration zone. Another type of gold
mineralization that was discovered using remote sensing is the gold associated with metachert in the Atmur
Desert.
Reducing Corrosion Rate by Welding DesignIJERD Editor
The paper addresses the importance of welding design to prevent corrosion at steel. Welding is
used to join pipe, profiles at bridges, spindle, and a lot more part of engineering construction. The
problems happened associated with welding are common issues in these fields, especially corrosion.
Corrosion can be reduced with many methods, they are painting, controlling humidity, and also good
welding design. In the research, it can be found that reducing residual stress on the welding can be
solved in corrosion rate reduction problem.
Preheating on 500oC and 600oC give better condition to reduce corosion rate than condition after
preheating 400oC. For all welding groove type, material with 500oC and 600oC preheating after 14 days
corrosion test is 0,5%-0,69% lost. Material with 400oC preheating after 14 days corrosion test is 0,57%-0,76%
lost.
Welding groove also influence corrosion rate. X and V type welding groove give better condition to reduce
corrosion rate than use 1/2V and 1/2 X welding groove. After 14 days corrosion test, the samples with
X welding groove type is 0,5%-0,57% lost. The samples with V welding groove after 14 days corrosion test is
0,51%-0,59% lost. The samples with 1/2V and 1/2X welding groove after 14 days corrosion test is 0,58%-
0,71% lost.
Router 1X3 – RTL Design and VerificationIJERD Editor
Routing is the process of moving a packet of data from source to destination and enables messages
to pass from one computer to another and eventually reach the target machine. A router is a networking device
that forwards data packets between computer networks. It is connected to two or more data lines from different
networks (as opposed to a network switch, which connects data lines from one single network). This paper,
mainly emphasizes upon the study of router device, it‟s top level architecture, and how various sub-modules of
router i.e. Register, FIFO, FSM and Synchronizer are synthesized, and simulated and finally connected to its top
module.
Active Power Exchange in Distributed Power-Flow Controller (DPFC) At Third Ha...IJERD Editor
This paper presents a component within the flexible ac-transmission system (FACTS) family, called
distributed power-flow controller (DPFC). The DPFC is derived from the unified power-flow controller (UPFC)
with an eliminated common dc link. The DPFC has the same control capabilities as the UPFC, which comprise
the adjustment of the line impedance, the transmission angle, and the bus voltage. The active power exchange
between the shunt and series converters, which is through the common dc link in the UPFC, is now through the
transmission lines at the third-harmonic frequency. DPFC multiple small-size single-phase converters which
reduces the cost of equipment, no voltage isolation between phases, increases redundancy and there by
reliability increases. The principle and analysis of the DPFC are presented in this paper and the corresponding
simulation results that are carried out on a scaled prototype are also shown.
Mitigation of Voltage Sag/Swell with Fuzzy Control Reduced Rating DVRIJERD Editor
Power quality has been an issue that is becoming increasingly pivotal in industrial electricity
consumers point of view in recent times. Modern industries employ Sensitive power electronic equipments,
control devices and non-linear loads as part of automated processes to increase energy efficiency and
productivity. Voltage disturbances are the most common power quality problem due to this the use of a large
numbers of sophisticated and sensitive electronic equipment in industrial systems is increased. This paper
discusses the design and simulation of dynamic voltage restorer for improvement of power quality and
reduce the harmonics distortion of sensitive loads. Power quality problem is occurring at non-standard
voltage, current and frequency. Electronic devices are very sensitive loads. In power system voltage sag,
swell, flicker and harmonics are some of the problem to the sensitive load. The compensation capability
of a DVR depends primarily on the maximum voltage injection ability and the amount of stored
energy available within the restorer. This device is connected in series with the distribution feeder at
medium voltage. A fuzzy logic control is used to produce the gate pulses for control circuit of DVR and the
circuit is simulated by using MATLAB/SIMULINK software.
Study on the Fused Deposition Modelling In Additive ManufacturingIJERD Editor
Additive manufacturing process, also popularly known as 3-D printing, is a process where a product
is created in a succession of layers. It is based on a novel materials incremental manufacturing philosophy.
Unlike conventional manufacturing processes where material is removed from a given work price to derive the
final shape of a product, 3-D printing develops the product from scratch thus obviating the necessity to cut away
materials. This prevents wastage of raw materials. Commonly used raw materials for the process are ABS
plastic, PLA and nylon. Recently the use of gold, bronze and wood has also been implemented. The complexity
factor of this process is 0% as in any object of any shape and size can be manufactured.
Spyware triggering system by particular string valueIJERD Editor
This computer programme can be used for good and bad purpose in hacking or in any general
purpose. We can say it is next step for hacking techniques such as keylogger and spyware. Once in this system if
user or hacker store particular string as a input after that software continually compare typing activity of user
with that stored string and if it is match then launch spyware programme.
A Blind Steganalysis on JPEG Gray Level Image Based on Statistical Features a...IJERD Editor
This paper presents a blind steganalysis technique to effectively attack the JPEG steganographic
schemes i.e. Jsteg, F5, Outguess and DWT Based. The proposed method exploits the correlations between
block-DCTcoefficients from intra-block and inter-block relation and the statistical moments of characteristic
functions of the test image is selected as features. The features are extracted from the BDCT JPEG 2-array.
Support Vector Machine with cross-validation is implemented for the classification.The proposed scheme gives
improved outcome in attacking.
Secure Image Transmission for Cloud Storage System Using Hybrid SchemeIJERD Editor
- Data over the cloud is transferred or transmitted between servers and users. Privacy of that
data is very important as it belongs to personal information. If data get hacked by the hacker, can be
used to defame a person’s social data. Sometimes delay are held during data transmission. i.e. Mobile
communication, bandwidth is low. Hence compression algorithms are proposed for fast and efficient
transmission, encryption is used for security purposes and blurring is used by providing additional
layers of security. These algorithms are hybridized for having a robust and efficient security and
transmission over cloud storage system.
Application of Buckley-Leverett Equation in Modeling the Radius of Invasion i...IJERD Editor
A thorough review of existing literature indicates that the Buckley-Leverett equation only analyzes
waterflood practices directly without any adjustments on real reservoir scenarios. By doing so, quite a number
of errors are introduced into these analyses. Also, for most waterflood scenarios, a radial investigation is more
appropriate than a simplified linear system. This study investigates the adoption of the Buckley-Leverett
equation to estimate the radius invasion of the displacing fluid during waterflooding. The model is also adopted
for a Microbial flood and a comparative analysis is conducted for both waterflooding and microbial flooding.
Results shown from the analysis doesn’t only records a success in determining the radial distance of the leading
edge of water during the flooding process, but also gives a clearer understanding of the applicability of
microbes to enhance oil production through in-situ production of bio-products like bio surfactans, biogenic
gases, bio acids etc.
Gesture Gaming on the World Wide Web Using an Ordinary Web CameraIJERD Editor
- Gesture gaming is a method by which users having a laptop/pc/x-box play games using natural or
bodily gestures. This paper presents a way of playing free flash games on the internet using an ordinary webcam
with the help of open source technologies. Emphasis in human activity recognition is given on the pose
estimation and the consistency in the pose of the player. These are estimated with the help of an ordinary web
camera having different resolutions from VGA to 20mps. Our work involved giving a 10 second documentary to
the user on how to play a particular game using gestures and what are the various kinds of gestures that can be
performed in front of the system. The initial inputs of the RGB values for the gesture component is obtained by
instructing the user to place his component in a red box in about 10 seconds after the short documentary before
the game is finished. Later the system opens the concerned game on the internet on popular flash game sites like
miniclip, games arcade, GameStop etc and loads the game clicking at various places and brings the state to a
place where the user is to perform only gestures to start playing the game. At any point of time the user can call
off the game by hitting the esc key and the program will release all of the controls and return to the desktop. It
was noted that the results obtained using an ordinary webcam matched that of the Kinect and the users could
relive the gaming experience of the free flash games on the net. Therefore effective in game advertising could
also be achieved thus resulting in a disruptive growth to the advertising firms.
Hardware Analysis of Resonant Frequency Converter Using Isolated Circuits And...IJERD Editor
-LLC resonant frequency converter is basically a combo of series as well as parallel resonant ckt. For
LCC resonant converter it is associated with a disadvantage that, though it has two resonant frequencies, the
lower resonant frequency is in ZCS region[5]. For this application, we are not able to design the converter
working at this resonant frequency. LLC resonant converter existed for a very long time but because of
unknown characteristic of this converter it was used as a series resonant converter with basically a passive
(resistive) load. . Here, it was designed to operate in switching frequency higher than resonant frequency of the
series resonant tank of Lr and Cr converter acts very similar to Series Resonant Converter. The benefit of LLC
resonant converter is narrow switching frequency range with light load[6] . Basically, the control ckt plays a
very imp. role and hence 555 Timer used here provides a perfect square wave as the control ckt provides no
slew rate which makes the square wave really strong and impenetrable. The dead band circuit provides the
exclusive dead band in micro seconds so as to avoid the simultaneous firing of two pairs of IGBT’s where one
pair switches off and the other on for a slightest period of time. Hence, the isolator ckt here is associated with
each and every ckt used because it acts as a driver and an isolation to each of the IGBT is provided with one
exclusive transformer supply[3]. The IGBT’s are fired using the appropriate signal using the previous boards
and hence at last a high frequency rectifier ckt with a filtering capacitor is used to get an exact dc
waveform .The basic goal of this particular analysis is to observe the wave forms and characteristics of
converters with differently positioned passive elements in the form of tank circuits.
Simulated Analysis of Resonant Frequency Converter Using Different Tank Circu...IJERD Editor
LLC resonant frequency converter is basically a combo of series as well as parallel resonant ckt. For
LCC resonant converter it is associated with a disadvantage that, though it has two resonant frequencies, the
lower resonant frequency is in ZCS region [5]. For this application, we are not able to design the converter
working at this resonant frequency. LLC resonant converter existed for a very long time but because of
unknown characteristic of this converter it was used as a series resonant converter with basically a passive
(resistive) load. . Here, it was designed to operate in switching frequency higher than resonant frequency of the
series resonant tank of Lr and Cr converter acts very similar to Series Resonant Converter. The benefit of LLC
resonant converter is narrow switching frequency range with light load[6] . Basically, the control ckt plays a
very imp. role and hence 555 Timer used here provides a perfect square wave as the control ckt provides no
slew rate which makes the square wave really strong and impenetrable. The dead band circuit provides the
exclusive dead band in micro seconds so as to avoid the simultaneous firing of two pairs of IGBT’s where one
pair switches off and the other on for a slightest period of time. Hence, the isolator ckt here is associated with
each and every ckt used because it acts as a driver and an isolation to each of the IGBT is provided with one
exclusive transformer supply[3]. The IGBT’s are fired using the appropriate signal using the previous boards
and hence at last a high frequency rectifier ckt with a filtering capacitor is used to get an exact dc
waveform .The basic goal of this particular analysis is to observe the wave forms and characteristics of
converters with differently positioned passive elements in the form of tank circuits. The supported simulation
is done through PSIM 6.0 software tool
Amateurs Radio operator, also known as HAM communicates with other HAMs through Radio
waves. Wireless communication in which Moon is used as natural satellite is called Moon-bounce or EME
(Earth -Moon-Earth) technique. Long distance communication (DXing) using Very High Frequency (VHF)
operated amateur HAM radio was difficult. Even with the modest setup having good transceiver, power
amplifier and high gain antenna with high directivity, VHF DXing is possible. Generally 2X11 YAGI antenna
along with rotor to set horizontal and vertical angle is used. Moon tracking software gives exact location,
visibility of Moon at both the stations and other vital data to acquire real time position of moon.
“MS-Extractor: An Innovative Approach to Extract Microsatellites on „Y‟ Chrom...IJERD Editor
Simple Sequence Repeats (SSR), also known as Microsatellites, have been extensively used as
molecular markers due to their abundance and high degree of polymorphism. The nucleotide sequences of
polymorphic forms of the same gene should be 99.9% identical. So, Microsatellites extraction from the Gene is
crucial. However, Microsatellites repeat count is compared, if they differ largely, he has some disorder. The Y
chromosome likely contains 50 to 60 genes that provide instructions for making proteins. Because only males
have the Y chromosome, the genes on this chromosome tend to be involved in male sex determination and
development. Several Microsatellite Extractors exist and they fail to extract microsatellites on large data sets of
giga bytes and tera bytes in size. The proposed tool “MS-Extractor: An Innovative Approach to extract
Microsatellites on „Y‟ Chromosome” can extract both Perfect as well as Imperfect Microsatellites from large
data sets of human genome „Y‟. The proposed system uses string matching with sliding window approach to
locate Microsatellites and extracts them.
Importance of Measurements in Smart GridIJERD Editor
- The need to get reliable supply, independence from fossil fuels, and capability to provide clean
energy at a fixed and lower cost, the existing power grid structure is transforming into Smart Grid. The
development of a smart energy distribution grid is a current goal of many nations. A Smart Grid should have
new capabilities such as self-healing, high reliability, energy management, and real-time pricing. This new era
of smart future grid will lead to major changes in existing technologies at generation, transmission and
distribution levels. The incorporation of renewable energy resources and distribution generators in the existing
grid will increase the complexity, optimization problems and instability of the system. This will lead to a
paradigm shift in the instrumentation and control requirements for Smart Grids for high quality, stable and
reliable electricity supply of power. The monitoring of the grid system state and stability relies on the
availability of reliable measurement of data. In this paper the measurement areas that highlight new
measurement challenges, development of the Smart Meters and the critical parameters of electric energy to be
monitored for improving the reliability of power systems has been discussed.
Study of Macro level Properties of SCC using GGBS and Lime stone powderIJERD Editor
One of the major environmental concerns is the disposal of the waste materials and utilization of
industrial by products. Lime stone quarries will produce millions of tons waste dust powder every year. Having
considerable high degree of fineness in comparision to cement this material may be utilized as a partial
replacement to cement. For this purpose an experiment is conducted to investigate the possibility of using lime
stone powder in the production of SCC with combined use GGBS and how it affects the fresh and mechanical
properties of SCC. First SCC is made by replacing cement with GGBS in percentages like 10, 20, 30, 40, 50 and
by taking the optimum mix with GGBS lime stone powder is blended to mix in percentages like 5, 10, 15, 20 as
a partial replacement to cement. Test results shows that the SCC mix with combination of 30% GGBS and 15%
limestone powder gives maximum compressive strength and fresh properties are also in the limits prescribed by
the EFNARC.
Saudi Arabia stands as a titan in the global energy landscape, renowned for its abundant oil and gas resources. It's the largest exporter of petroleum and holds some of the world's most significant reserves. Let's delve into the top 10 oil and gas projects shaping Saudi Arabia's energy future in 2024.
Immunizing Image Classifiers Against Localized Adversary Attacksgerogepatton
This paper addresses the vulnerability of deep learning models, particularly convolutional neural networks
(CNN)s, to adversarial attacks and presents a proactive training technique designed to counter them. We
introduce a novel volumization algorithm, which transforms 2D images into 3D volumetric representations.
When combined with 3D convolution and deep curriculum learning optimization (CLO), itsignificantly improves
the immunity of models against localized universal attacks by up to 40%. We evaluate our proposed approach
using contemporary CNN architectures and the modified Canadian Institute for Advanced Research (CIFAR-10
and CIFAR-100) and ImageNet Large Scale Visual Recognition Challenge (ILSVRC12) datasets, showcasing
accuracy improvements over previous techniques. The results indicate that the combination of the volumetric
input and curriculum learning holds significant promise for mitigating adversarial attacks without necessitating
adversary training.
NUMERICAL SIMULATIONS OF HEAT AND MASS TRANSFER IN CONDENSING HEAT EXCHANGERS...ssuser7dcef0
Power plants release a large amount of water vapor into the
atmosphere through the stack. The flue gas can be a potential
source for obtaining much needed cooling water for a power
plant. If a power plant could recover and reuse a portion of this
moisture, it could reduce its total cooling water intake
requirement. One of the most practical way to recover water
from flue gas is to use a condensing heat exchanger. The power
plant could also recover latent heat due to condensation as well
as sensible heat due to lowering the flue gas exit temperature.
Additionally, harmful acids released from the stack can be
reduced in a condensing heat exchanger by acid condensation. reduced in a condensing heat exchanger by acid condensation.
Condensation of vapors in flue gas is a complicated
phenomenon since heat and mass transfer of water vapor and
various acids simultaneously occur in the presence of noncondensable
gases such as nitrogen and oxygen. Design of a
condenser depends on the knowledge and understanding of the
heat and mass transfer processes. A computer program for
numerical simulations of water (H2O) and sulfuric acid (H2SO4)
condensation in a flue gas condensing heat exchanger was
developed using MATLAB. Governing equations based on
mass and energy balances for the system were derived to
predict variables such as flue gas exit temperature, cooling
water outlet temperature, mole fraction and condensation rates
of water and sulfuric acid vapors. The equations were solved
using an iterative solution technique with calculations of heat
and mass transfer coefficients and physical properties.
Using recycled concrete aggregates (RCA) for pavements is crucial to achieving sustainability. Implementing RCA for new pavement can minimize carbon footprint, conserve natural resources, reduce harmful emissions, and lower life cycle costs. Compared to natural aggregate (NA), RCA pavement has fewer comprehensive studies and sustainability assessments.
Student information management system project report ii.pdfKamal Acharya
Our project explains about the student management. This project mainly explains the various actions related to student details. This project shows some ease in adding, editing and deleting the student details. It also provides a less time consuming process for viewing, adding, editing and deleting the marks of the students.
Cosmetic shop management system project report.pdfKamal Acharya
Buying new cosmetic products is difficult. It can even be scary for those who have sensitive skin and are prone to skin trouble. The information needed to alleviate this problem is on the back of each product, but it's thought to interpret those ingredient lists unless you have a background in chemistry.
Instead of buying and hoping for the best, we can use data science to help us predict which products may be good fits for us. It includes various function programs to do the above mentioned tasks.
Data file handling has been effectively used in the program.
The automated cosmetic shop management system should deal with the automation of general workflow and administration process of the shop. The main processes of the system focus on customer's request where the system is able to search the most appropriate products and deliver it to the customers. It should help the employees to quickly identify the list of cosmetic product that have reached the minimum quantity and also keep a track of expired date for each cosmetic product. It should help the employees to find the rack number in which the product is placed.It is also Faster and more efficient way.
Cosmetic shop management system project report.pdf
E1082935
1. International Journal of Engineering Research and Development
e-ISSN: 2278-067X, p-ISSN: 2278-800X, www.ijerd.com
Volume 10, Issue 8 (August 2014), PP.29-35
Comparison of Voltage Sag and Swell Detection Algorithms
In Power System
R. Madhan mohan S. Mahaboob basha A. Subramanyam
Assistant Professor, Dept. EEE Assistant Professor, Dept. EEE PG Student, Dept. EEE
A.I.T.S-Rajampet, A.P, INDIA A.I.T.S-Rajampet, A.P, INDIA A.I.T.S-Rajampet, A.P, INDIA
Abstract:- Power quality issues have been a source of major concern in recent years due to extensive use of
power electronic devices and non-linear loads in electrical power system. Voltage sags and swells is a common
power system disturbance, usually associated with power system faults. Therefore the effective detection of
voltage sags and swells event is an important issue for both voltage sag and swell analysis and mitigation. There
are several detection methods for voltage sags and swells such as RMS voltage detection, peak voltage
detection, and Fourier transform methods. The problem with these methods is that they use a windowing
technique and can therefore be too slow when applied to detect voltages sags for mitigation since they use
historical value, not instantaneous value which may lead to long detection time when voltage sag has occurred.
A novel algorithm require for voltage sag detection. The algorithm can extract a single non-stationary
sinusoidal signal out of a given multi component input signal. The algorithm is capable of estimating the
amplitude, phase and frequency of an input signal in real time. No complex mathematics is required for
implementation of the algorithm. It is compared to other methods of sag detection and same procedure for swell
also.
Keywords:- Power quality, peak voltage detection, rms voltage detection, voltage sag.
I. INTRODUCTION
Voltage sag and swell may be caused by switching operations associated with a temporary
disconnection of supply, the flow of inrush currents associated with the starting of motor loads, or the flow of
fault currents. These events may emanate from the customers system or from the public network. A power
system fault is a typical cause of a voltage sag. Faults occurs in transmission (EHV), sub transmission (HV),
medium-voltage (MV), and low-voltage (LV) systems and the sags propagate throughout the power system. The
sag distribution experienced by a low-voltage customer includes all these sags of different origin. Due to the
increasing use of sensitive equipment, voltage sags have become in recent years, one of the central power-quality
(PQ) concerns faced by utilities and customers. So as the voltage sags are very serious problem now a
days. The very essential step before analyzing any power quality disturbances is detection. Accurate detection of
undesired transient disturbances is very important to provide better service.
Much of the research in recent years has focused on the hardware performance of mitigation devices,
B. P. Roberts et.al [7,8,9]. Surveys have shown that voltage sags and swells are considered as the dominant
factor affecting power quality. Voltage sags can generally be characterized by sag magnitude, duration, and
frequency. The sag magnitude detect by so many methods among mainly R.M.S, Peak Detection, D.F.T
methods used in last decays and same as for swells also.
But these methods have some limitations are, the disadvantage of R.M.S method is that a window of
historical data has to be obtained, processed and then only can a mitigation signal be sent to the hardware. Due
to use of a low-pass filter and instantaneous reactive power theory to extract the voltage sag, this is complex for
implementation in a digital signal processor or micro-controller (Raj Naidoo, Pragasen Pillay, et al, 2007).The
DFT is ideal for calculating magnitudes of the steady-state sinusoidal signals but it does not have the capability
of coping with sharp changes and discontinuities in signals.
The main objective is to be proposing a novel algorithm for rapid voltage sag detection better than
other methods. This algorithm has the ability to track the amplitude of the voltage sag in real time. Proposed
novel algorithm was compared to existing sag detection methods to show its fastness and robustness. The
algorithms for voltage sag and swell detection using MATLAB/SIMULINK software.
This paper is organized as below. In Section II, the description of voltage sag detection methods is
presented. Implementation of proposed algorithm is described in section III. In Section IV, the results and
discussions are explained. Finally, the conclusion of this paper is presented in Section V.
29
2. Comparison of Voltage Sag and Swell Detection Algorithms in Power System
II. DESCRIPTION OF METHODS
30
A. RMS Value Evaluation Method
RMS (voltage or current) is a quantity commonly used in power systems as an easy way of accessing
and describing power system phenomena. The rms value can be computed each time a new sample is obtained
but generally these values are updated each cycle or half cycle. If the rms values are updated every time a new
sample is obtained, then the calculated rms series is called continuous. If the updating of rms is done with a
certain time interval, then the obtained rms is called discrete. As long as the voltage is sinusoidal, it does not
matter whether RMS voltage, fundamental voltage, or peak voltage is used to obtain the sag magnitude. But the
RMS voltage, related to power calculation, make it more suitable for the characterization of the magnitude of
voltage sag.
Voltage signals are recorded as sampled points in time and the RMS value of a sampled time-domain
signal is calculated.
푉푟푚푠 =
1
푁
2 =1 푣푖
(1)
푖
푁Where N is the number of samples per cycle and vi is the magnitudes of sampled signal. Real rms is
obtained if the window length N is set to one cycle. In practical application, the data w interval. In order to
distinguish each result, time instant stamps labelled K are added to rms voltage as independent variable i.e., it
makes rms voltage to be a function of time.
Rewrite the eq. (1) to the sequence, shown as follows
푉푟푚푠 (푘) =
1
푁
푖=푘 푣2
푖=푘−푁+1 푖
(2)
The time stamp k is restricted to be an integer that is equal to or greater than 1. Each value from (2) is
obtained over the processing window. RMS calculation can also be performed by considering samples for one
half-cycle. The window length has to be an integer multiple of one-half cycle. Any other window length will
produce an oscillation in the rms plot with a frequency twice the fundamental frequency.
B. Peak Voltage Detection Method
Voltage sag can be detected by calculating the peak value of the signal waveform. A Two-sample
technique, based on the assumption of having pure sinusoidal voltage waveform, is used for peak voltage
estimation, by finding the maximum of the absolute value of the sampled signal over half cycle propagating
window.
Let v(n), v(n+1) be voltage samples measured at times t(n), t(n+1) respectively, and let Δt be the
sampling time interval. Then
푣 푛 = 푉푠푖푛 푛 − 1 푤0푇푠 (3)
푣 푛 + 1 = 푉푠푖푛 푛푤0푇푠 (4)
= 푉푠푖푛 푛 − 1 푤0푇푠 푐표푠 푤0푇푠 + 푉푐표푠((푛 − 1)푤0푇푠)푠푖푛(푤0푇푠)
Substituting (3) into (4) and simplifying result in
푉푐표푠 푛 − 1 푤0푇푠 =
푣 푛 + 1 − 푣(푛)푐표푠(푤0푇푠)
푠푖푛(푤0푇푠)
(5)
Adding the squares of (3) and (5) and then take the square root of the results, the corresponding equation
the signal peak is simply
푉푐표푠 푛 − 1 푤0푇푠 =
푣 푛 + 1 − 푣(푛)푐표푠(푤0푇푠)
푠푖푛(푤0푇푠)
(6)
Because the detector is based on the concept of an orthogonal function pair, it is called "Orthogonal
detector". The significant advantage of the peak evaluation compared to others method is that only needs single
phase values.
C. Discrete Fourier Transform (DFT) Method
In practice data are always available in the form of a sampled time function, represented by a time
series of amplitudes, separated by fixed time intervals of limited duration. When dealing with such data a
modification of the Fourier transform, the DFT (Discrete Fourier transform) is used. The implementation of the
DFT by means of FFT algorithm forms the basis of the most modern spectral and harmonic analysis systems.
DFT transforms a signal from the time domain to the frequency domain. This makes available the
amplitude and phase of the fundamental and the harmonics present in the signal. The dc component is also
available in the first bin.
3. Comparison of Voltage Sag and Swell Detection Algorithms in Power System
The Fast Fourier Transform (FFT) is the DFT’s computational efficient implementation, its fast
computation is considered as an advantage. With this tool it is possible to have an estimation of the fundamental
amplitude and its harmonics with reasonable approximation. FFT performs well for estimation of periodic
signals in stationary state; however it does not perform well for detection of sudden or fast changes in waveform
e.g. transients or voltage sags. In some cases, results of estimation can be improved with windowing, i.e.
Hanning, Hamming or Kaiser window By applying Fourier transform to each supply phase, it is possible to
obtain the magnitude and phase of each of the frequency components of the supply waveform. The fundamental
voltage component is extracted normally from a time sequence over a fundamental frequency cycle. The source
voltage v(t) can be expressed as the following equation using the Fourier series[11].
31
푉 푡 =
푎0
2
∞
+ 푎푛 푐표푠 푛푤0푡 + 푏푛 푠푖푛 푛푤0푡
푛=0
(7)
The fundamental component for n= 1 is obtained, separating the real and imaginary parts.
푎1 =
2
푇
푇
푣(푡)푐표푠푤0푡푑푡
(8)
0 푏1 =
2
푇
푣(푡)푠푖푛푤0푡푑푡
푇
0
(9)
By applying the DFT for (8) and (9), (10) and (11) are obtained.
푎1 = 2
푁
푣 푡 − 푖푇
푁 푐표푠 2휋 푖
푁 (10)
푏1 = 2
푁
푣 푡 − 푖푇
푁 푠푖푛 2휋 푖
푁 (11)
Using the values of a, and hi, the magnitude of the fundamental component can be easily obtained as follows:
푉 = 푎1
2 + 푏1
2 (12)
Window length dependency resolution is a disadvantage e.g. the longer the data window (N) the better the
frequency resolution
Sets of sliding window DFTs can however be can be used to analyze non-stationary signals.
D. Novel Algorithm
Let V(t) represent a voltage signal in which n(t) denotes the superimposed disturbance or noise. For power
system operation, parameters V,w and δ are functions of time
∞
푉 푡 = 푉푖 푠푖푛(푤푡 + 휙) + 푛(푡)
푛=1
(13)
In the case of power systems, this function is usually continuous and almost periodic. A sinusoidal
component of this function is
푠 푡 = 푉푖 푠푖푛 푤푡 + 훿푠 (14)
In which Vs is the amplitude, W the frequency (in rad/s), and δ is the phase angle. During power system
operation, parameters Vs, W, and δ vary with time depending on load changes and faults. For sag analysis and
detection, the important parameters are sag magnitude, duration and phase angle jump.
A sag is detected when Vs goes below 0.9 p.u of the declared voltage. Let M be the manifold containing all
sinusoidal signals
푀 푡 = {푉(푡)푠푖푛(푤 푡 + 훿))} (15)
Where
V t ∈ Vmin , Vmax ,
w t ∈ wmin ,wmax ,
δ t ∈ [δmin , δmax ]
Therefore
ℑ 푡 = [푉 푡 , 푤 푡 , 훿(푡)]푇 (16)
is the vector of parameters that belong to the parameter space
푉 푡 = [푉, 푤, 훿]푇 (17)
And T denotes the transposition matrix. The output is defined as the desired sinusoidal component, namely
푠 푡, ℑ 푡 = 푉 푡 푠푖푛 푤 푡 푡 + 훿 푡 18
To extract a certain sinusoidal component of V(t) , the solution has to be an optimumϕ that minimizes the
distance function between s(t, ϕ(t))and V(t)
ℑ표푝푡 = 푎푟푔
푚푖푛
ℑ(푡) ∈ 푣
푑 푠 푡, ℑ 푡 , 푣 푡 (19)
4. Comparison of Voltage Sag and Swell Detection Algorithms in Power System
Without being concerned about the mathematical correctness of the definition of the least squares error
which, strictly speaking, has to map onto the set of real numbers, the instantaneous distance function d is used.
푑2 푡, ℑ 푡 = [푣 푡 − 푠 푡, ℑ 푡 ]2 ≜ 푒(푡)2 (20)
32
The cost function is defined as
퐽 푡, ℑ 푡 ≜ 푑2 푡, ℑ 푡 (21)
Although the cost function is estimated using the gradient decent method not quadratic, the parameter
vector -3 is
푑ℑ(푡)
푑푡
= −휇
휕[퐽(푡, ℑ(푡))
휕ℑ(푡)
(22)
The estimated parameter vector is denoted by
ℑ 푡 = 푣 푡 , 푤 푡 , 훿 푡
푇
23
The governing set of equations for the algorithm is
푉 = 푘1푒 푠푖푛 ∅
푤 = 푘2푒푉 푐표푠 ∅
∅ = 푘3푒퐴 푐표푠 ∅ + 푤
푠 푡 = 푉 푠푖푛 ∅
푒 푡 = 푣 푡 − 푠 푡
Where v t and s t are the input and output signals to the core algorithm, respectively. The dot
represents the differentiation with respect to time and the error signal e t is v t − s t . State variables V, f and
w directly provide estimates of amplitude, phase, frequency of v(t). Parametersk1, k2andk3,are positive
numbers that determine the behaviour of the algorithm in terms convergence speed and accuracy. Specifically,
parameter h controls the speed of the transient response of the algorithm with respect to variations in the
amplitude of the interfering signal. Parameters band b mutually control the speed of the transient response of the
algorithm with respect to variations in the frequency of the interfering signal.
III. IMPLENTATION OF PROPOSED ALGORITHM
The dynamics of the algorithm presents a notch filter in the sense that it extracts one specific sinusoidal
component and rejects all other components including noise. It is adaptive in the sense that the notch filter
accommodates variations of the characteristics of the desired output over time. The centre frequency of such an
adaptive notch filter is specified by the initial condition of frequency. It is in the form of the composition of
simple blocks suitable for schematic software development tools. Implementation of the proposed algorithm
entails the discretization of the differential equations describing the algorithm. The discredited form of the
governing equations of the proposed algorithm can be written as:
푉 푛 + 1 = 푉 푛 + 2푇푠 푘1푒 푛 푠푖푛휙 푛 (24)
푤 푛 + 1 = 푤 푛 + 2푇푠 푘2푒 푛 푉 푛 푐표푠휙 푛 (25)
휙 푛 + 1 = 휙 푛 + 푇푠+2푇푠 푘2푘3푒 푛 푉 푛 푐표푠휙 푛 (26)
푠 푛 = 푉 푛 푠푖푛휙 푛 27
푒 푛 = 푉 푛 − 푠 푛 (28)
First order approximation for derivatives is assumed, Ts is the sampling time and n is the time index.
The values of the k parameters determine the convergence speed of the algorithm. The valves of the k
parameters have to be chosen such that the two conditions 0 < k1 < 2f0 and 0 < k2 < (
2f0
v
) of are roughly
satisfied. Quantity f0 is the frequency of the sinusoidal signal of interest and V is the amplitude. The choice of
k3 is the independent of k2• The proposed algorithm is found to be robust not only with regards to its internal
structure, but most importantly with regards to the adjustment of its k parameters.
The terms of the engineering performance of the system, this indicates that the output of the system
will approach a sinusoidal component of the input signal. Moreover, time variations of the parameters in V(t)
are tolerated by the system. One of the issues that needs to be considered when using the proposed algorithm is
the setting of its parametersk1,. The valve of the parameters k1, k2andk3 determine the convergence speed
versus error compromise.
Simulations were performed to test the performance of the proposed algorithm and to verify its ability
of detecting voltage sags and swell by using mat lab software.
5. Comparison of Voltage Sag and Swell Detection Algorithms in Power System
Fig. 1 Simulation Block Diagram
IV. RESULTS AND DISCUSSIONS
33
A. Algorithm Method for Voltage Sag Detection
The algorithm is capable of extracting sinusoidal component in a highly noisy input signal and
demonstrates the ability of the algorithm to track a voltage sag in real time. The algorithm has the ability to track
the sag. Additional parameters that can be include the system frequency and phase angle jump at sag initiation.
Fig. 2 Extraction of a sinusoid Sag tracking a voltage Fig. 3 Comparison between R.M.S and
algorithm for voltage sag detection
B. Comparison of RMS Voltage and Algorithm Method
The result of MATLAB Program shows comparison between the one-cycle rms voltage sag with the
algorithm as shown in Fig. 3.0 It shows the sag imitation point, the rms, and the algorithm. The proposed
algorithm detects sag at 106.8 m.sec, while the one cycle rms detects it at 110.8ms.The difference in detection
time between the two methods is 5 ms.
C. Comparison of Peak Voltage and Algorithm Method
Fig. 4 shows the performance of the peak voltage detection method when compared to the algorithm.
The algorithm detects the sag at 106.8 ms and the peak voltage method at 108.2 ms. So that difference in sag
detection time of 1.4 ms
Fig. 4 Comparison between peak and algorithm for voltage sag detection Fig. 5 Comparison between
DFT and algorithm for voltage sag detection
D. Comparison of DFT and Algorithm Method
sag estimation Fig. 5 shows the comparison of the proposed algorithm and DFT for voltage sag
detecting in real time. DFT detects the sag at 109.4 ms, and the difference in detection time is 2.6 ms. The
6. Comparison of Voltage Sag and Swell Detection Algorithms in Power System
simulation results show that the algorithm is faster to detect the starting of the voltage sag. The estimation of sag
magnitude is not much difference and do not affect the
34
E. Algorithm Method for Voltage Swell Detection
A typical set of k parameters, used in the algorithm for voltage swell detections is k1, = 1000, k2 = 1000
and k3 = 0.02. Where the values of k1, and k2 are normalized with respect to the nominal frequency of the
incoming signal. Fig. 6 shows that the algorithm is capable of extracting sinusoidal component in a highly noisy
input signal. Fig. 6 shows the input signal, extracted signal amplitude and demonstrates the ability of the
algorithm to track a voltage swell in real time
Fig. 6 Extraction of a sinusoid Sag tracking a voltage Fig. 7 Comparison between R.M.S and algorithm
for voltage swell detection
F. Comparison of RMS Voltage and Algorithm Method
The result of MATLAB Program shows comparison between the half-cycle rms voltage sag with the
algorithm as shown in Fig. 7. It shows the swell imitation point, the rms, and the algorithm. The proposed
algorithm detects sag at 0.1013sec , while the one cycle rms detects it at 0.1032sec.The difference in detection
time between the two methods is 19ms
G. Comparison of Peak Voltage and Algorithm Method
Fig. 8 shows the performance of the peak voltage detection method when compared to the algorithm.
The algorithm detects the swell at 101.3 ms and the peak voltage method at 102.9 ms. That results in a
difference in sag detection time of 1.6 ms.
Fig. 8 Comparison between peak and algorithm for voltage swell detection
Fig. 9 Comparison between DFT and algorithm for voltage sag detection
H. Comparison of DFT and Algorithm Method
Fig. 9 shows the comparison of the proposed algorithm and DFT for voltage sag detecting in real time.
DFT detects the sag at 103.1 ms, and the difference in detection time is 2. 1ms.The simulation results show that
the algorithm is faster to detect the starting of the voltage sag. The estimation of sag magnitude is not much
difference and do not affect the sag estimation
V. SUMMARY
Voltage sag and swell can be detected with R.M.S, Peak voltage detection method, DFT and new
algorithm on MAT LAB/SIMULINK software successfully.Table.10 and Table.11 shows the time taken to
detects sag or swell and shows delay time compared with actual applied time.
7. Comparison of Voltage Sag and Swell Detection Algorithms in Power System
Table10: Time taken to detects sag by different methods Table 11: Time taken to detects sag by different methods
The comparison between proposed method and other methods gives clarity about how much fast
35
magnitude can detected
VI. CONCLUSION
The New algorithm was successfully tested for the voltage sag and swell detection in distribution
network in MATLAB environment. The MATLAB results illustrate the capability of the proposed algorithm to
detect voltage sag in real time. The proposed algorithm has been compared with the rms voltage sag detection
method, DFT and Peak voltage. Simulation results shows that the proposed algorithm able to detect the sag
faster than the conventional methods. It has the ability to track the amplitude. Phase and frequency of a voltage
signal in real time. No complex mathematics is required for implementation of the algorithm on a digital signal
processor. This is distinct advantage over other methods of sag detection.
REFERENCES
[1]. Suresh Kamble and Dr.Chandrashekhra Thorat," A New method for Voltage Sag Detection" IEEE-International
Conference on Advances in Engineering, Science and Management (lCAESM -2012)
March 2012.
[2]. "IEEE Recommended Practice for Monitoring Electric Power Quality," IEEE Std. 1159-1995, June
1995.
[3]. "IEEE Guide for Service to Equipment Sensitive to Momentary Voltage "IEEE Std 1250-1995.
[4]. C.Mestres," Computer Power Supply, analysis of service quality in voltage dips field." Revue
journal of electrical power supply 81(9):531-6
[5]. F.Tosato and G.Giadrossi, et al."The problems posed by voltage supply dips to industrial power
electronic loads", 6th Mediterranean Conference Electro technical Proceedings (Cat.No.91CH2964-
5),22-24 May 1991,Slovenia,IEEE.
[6]. M. H. J. Bollen, Understanding Power Quality Problems: Voltage Sags and Interruptions. New York:
IEEE Press, 1999, vol. I.
[7]. B. P. Roberts, “Energy storage applications for large scale power protection systems,” in Proc. Transm.
Diatribe. Conf. Expo., 2001, pp. 1157–1160.
[8]. P. Wang, N. Jenkins, and M. H. J. Bollen, “Experimental investigation of voltage sag mitigation by an
advanced static Var compensator,” IEEE Trans. Power Del., vol. 13, no. 4, pp. 1461–1467, Oct. 1998.
[9]. J. C. Gomez and G. N. Campetelli, “Voltage sag mitigation by current limiting fuses,” in Proc. Industry
Applications Conf., 2000, pp. 3202–3207.
[10]. Dong-Jun Wan, Sean-Ju Ahn and Yop Chung, "A new definition of voltage sag duration considering
the voltage tolerance curve," IEEE Bologna Power Tech. Conference, Bologna, Italy, vol.4, June 23-
26, 2003.
[11]. B. Bae, J. Lee, J. Jeong, and B. Han, "Line-Interactive Single-Phase Dynamic Voltage Restorer With
Novel Sag Detection Algorithm," IEEE Transactions on Power Delivery, Vol. 25, No. 4, pp.2702-2708,
October 2010.
[12]. M.Popescu and F.Popescu"The quality of delivered electric power quality indices of the electric
voltage in the presence of a deforming regime" Energetica 31(4):182-9,1983.
[13]. B.Hairabedian,"A System for surveying power quality", IEEE Instrumentation and Measurement
Technology Conference (Cat.No.89CH2707-8), 25-27, April, 1989 Washington, DC, USA.
[14]. D.S.Dorr "Power quality study-1990 to1995-intial reasults".APEC'92.Seventh Annual Applied Power
Electronics Conference and Exposition.1992 (Cat.No.92CH3089-0), 23-27 Feb.1992, Boston, MA,
USA.
[15]. E.J.Delaney, D.R.Mueller,et, et.al."A major UK distribution power quality survey" Universities Power
Engineering Conference (UPEC),14-16 ept.1994,Galway,Ierland.