This document discusses accurate harmonic source identification in power distribution systems using time-frequency analysis with the S-transform. The key points are:
1. The S-transform is proposed for harmonic source identification as it provides better frequency resolution for low frequencies and time resolution for high frequencies compared to other time-frequency analysis techniques.
2. The method involves measuring voltage and current at the point of common coupling and applying the S-transform to obtain the time-frequency representation of the signals.
3. Spectral impedances are extracted from the time-frequency impedance representation, including the fundamental impedance and harmonic impedances. The relationship between these impedances is then used to identify the harmonic source location.
An Improved of Multiple Harmonic Sources Identification in Distribution Syste...IAES-IJPEDS
This paper introduces an improved of multiple harmonic sources
identification that been produced by inverter loads in power system using
time-frequency distribution (TFD) analysis which is spectrogram.
The spectrogram is a very applicable method to represent signals in
time-frequency representation (TFR) and the main advantages
of spectrogram are the accuracy, speed of the algorithm and use low memory
size such that it can be computed rapidly. The identification of multiple
harmonic sources is based on the significant relationship of spectral
impedances which are the fundamental impedance (Z1) and harmonic
impedance (Zh) that extracted from TFR. To verify the accuracy of the
proposed method, MATLAB simulations carried out several unique cases
with different harmonic producing loads on IEEE 4-bus test feeder cases. It is
proven that the proposed method is superior with 100% correct identification
of multiple harmonic sources. It is envisioned that the method is very
accurate, fast and cost efficient to localize harmonic sources in distribution
system.
A Diagnostic Analytics of Harmonic Source Signature Recognition by Using Peri...IJECEIAES
This paper presents a diagnostic analytics of harmonic source signature recognition of rectifier and inverter-based load in the distribution system with single-point measurement at the point of common coupling by utilizing Periodogram. Signature recognition pattern is used to distinguish the harmonic sources accurately by obtaining the distribution of harmonic and interharmonic components and the harmonic contribution changes. This is achieved by using the significant signature recognition of harmonic producing load obtained from analysing the harmonic contribution changes. Based on voltage and current signature analysis, the distribution of harmonic components can be divided into three zones. To distinguish between the harmonic producing loads, the harmonic components are observed at these zones to get the signature recognition pattern. The result demonstrate that periodogram technique accurately diagnose and distinguish the type of harmonic sources in the distribution system
System Performance Analysis of Half-Duplex Relay Network over Rician Fading C...TELKOMNIKA JOURNAL
In this paper, the system performance of an amplify-and-forward (AF) relaying network over
Rician Fading Channel is proposed, analyzed and demonstrated. For details this analysis, the energy and
information are transferred from the source to the relay nodes by two methods: 1) time switching protocol
and 2) power splitting protocol. Firstly, due to the constraint of the wireless energy harvesting at the relay
node, the analytical mathematical expressions of the achievable throughput and the outage probability of
both schemes were proposed and demonstrated. After that, the effect of various system parameters on the
system performance is rigorously studied with closed-form expressions for the system performance.
Finally, the analytical results are also demonstrated by Monte-Carlo simulation in comparison with the
closed-form expressions. The numerical results demonstrated the effect of various system parameters,
such as energy harvesting time, power splitting ratio, source transmission to noise power, and the
threshold value, on the system performance of AF wireless relay nodes. The results show that the
analytical mathematical and simulated results match for all possible parameter values for both schemes.
An Improved Detection and Classification Technique of Harmonic Signals in Pow...Yayah Zakaria
This paper introduces an improved detection and classification technique of harmonic signals in power distribution using time-frequency distribution (TFD) analysis which is spectrogram. The spectrogram is an appropriate approach to signify signals in jointly time-frequency domain and known as time frequency representation (TFR). The spectral information of signals can
be observed and estimated plainly from TFR due to identify the
characteristics of the signals. Based on rule-based classifier and the threshold settings that referred to IEEE Standard 1159 2009, the detection and classification of harmonic signals for 100 unique signals consist of various characteristic of harmonics are carried out successfully. The accuracy of proposed method is examined by using MAPE and the result show that the technique provides high accuracy. In addition, spectrogram also gives 100 percent correct classification of harmonic signals. It is proven that the proposed method is accurate, fast and cost efficient for detecting and classifying harmonic signals in distribution system.
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).
A Critical Review of Time-frequency Distribution Analysis for Detection and C...IJECEIAES
This paper presents a critical review of time-frequency distributions (TFDs) analysis for detection and classification of harmonic signal. 100 unique harmonic signals comprise of numerous characteristic are detected and classified by using spectrogram, Gabor transform and S-transform. The rulebased classifier and the threshold settings of the analysis are according to the IEEE Standard 1159 2009. The best TFD for harmonic signals detection and classification is selected through performance analysis with regards to the accuracy, computational complexity and memory size that been used during the analysis.
Peak detection using wavelet transformIJCNCJournal
A new work based-wavelet transform is designed to overcome one of the main drawbacks that found in the
present new technologies. Orthogonal Frequency Division Multiplexing (OFDM)is proposed in the
literature to enhance the multimedia resolution. However, the high peak power (PAPR) values will obstruct
such achievements. Therefore, a new proposition is found in this work, making use of the wavelet
transforms methods, and it is divided into three main stages; de-noising stage, thresholding stage and then
the replacement stage.
In order to check the system stages validity; a mathematical model has been built and its checked after
using a MATLAB simulation. A simulated bit error rate (BER) achievement will be compared with our
previously published work, where an enhancement from 8×10-1 to be 5×10-1 is achieved. Moreover, these
results will be compared to the work found in the literature, where we have accomplished around 27%
PAPR extra reduction.
As a result, the BER performance has been improved for the same bandwidth occupancy. Moreover and
due to the de-noise stage, the verification rate has been improved to reach 81%. This is in addition to the
noise immunity enhancement.
An Improved of Multiple Harmonic Sources Identification in Distribution Syste...IAES-IJPEDS
This paper introduces an improved of multiple harmonic sources
identification that been produced by inverter loads in power system using
time-frequency distribution (TFD) analysis which is spectrogram.
The spectrogram is a very applicable method to represent signals in
time-frequency representation (TFR) and the main advantages
of spectrogram are the accuracy, speed of the algorithm and use low memory
size such that it can be computed rapidly. The identification of multiple
harmonic sources is based on the significant relationship of spectral
impedances which are the fundamental impedance (Z1) and harmonic
impedance (Zh) that extracted from TFR. To verify the accuracy of the
proposed method, MATLAB simulations carried out several unique cases
with different harmonic producing loads on IEEE 4-bus test feeder cases. It is
proven that the proposed method is superior with 100% correct identification
of multiple harmonic sources. It is envisioned that the method is very
accurate, fast and cost efficient to localize harmonic sources in distribution
system.
A Diagnostic Analytics of Harmonic Source Signature Recognition by Using Peri...IJECEIAES
This paper presents a diagnostic analytics of harmonic source signature recognition of rectifier and inverter-based load in the distribution system with single-point measurement at the point of common coupling by utilizing Periodogram. Signature recognition pattern is used to distinguish the harmonic sources accurately by obtaining the distribution of harmonic and interharmonic components and the harmonic contribution changes. This is achieved by using the significant signature recognition of harmonic producing load obtained from analysing the harmonic contribution changes. Based on voltage and current signature analysis, the distribution of harmonic components can be divided into three zones. To distinguish between the harmonic producing loads, the harmonic components are observed at these zones to get the signature recognition pattern. The result demonstrate that periodogram technique accurately diagnose and distinguish the type of harmonic sources in the distribution system
System Performance Analysis of Half-Duplex Relay Network over Rician Fading C...TELKOMNIKA JOURNAL
In this paper, the system performance of an amplify-and-forward (AF) relaying network over
Rician Fading Channel is proposed, analyzed and demonstrated. For details this analysis, the energy and
information are transferred from the source to the relay nodes by two methods: 1) time switching protocol
and 2) power splitting protocol. Firstly, due to the constraint of the wireless energy harvesting at the relay
node, the analytical mathematical expressions of the achievable throughput and the outage probability of
both schemes were proposed and demonstrated. After that, the effect of various system parameters on the
system performance is rigorously studied with closed-form expressions for the system performance.
Finally, the analytical results are also demonstrated by Monte-Carlo simulation in comparison with the
closed-form expressions. The numerical results demonstrated the effect of various system parameters,
such as energy harvesting time, power splitting ratio, source transmission to noise power, and the
threshold value, on the system performance of AF wireless relay nodes. The results show that the
analytical mathematical and simulated results match for all possible parameter values for both schemes.
An Improved Detection and Classification Technique of Harmonic Signals in Pow...Yayah Zakaria
This paper introduces an improved detection and classification technique of harmonic signals in power distribution using time-frequency distribution (TFD) analysis which is spectrogram. The spectrogram is an appropriate approach to signify signals in jointly time-frequency domain and known as time frequency representation (TFR). The spectral information of signals can
be observed and estimated plainly from TFR due to identify the
characteristics of the signals. Based on rule-based classifier and the threshold settings that referred to IEEE Standard 1159 2009, the detection and classification of harmonic signals for 100 unique signals consist of various characteristic of harmonics are carried out successfully. The accuracy of proposed method is examined by using MAPE and the result show that the technique provides high accuracy. In addition, spectrogram also gives 100 percent correct classification of harmonic signals. It is proven that the proposed method is accurate, fast and cost efficient for detecting and classifying harmonic signals in distribution system.
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).
A Critical Review of Time-frequency Distribution Analysis for Detection and C...IJECEIAES
This paper presents a critical review of time-frequency distributions (TFDs) analysis for detection and classification of harmonic signal. 100 unique harmonic signals comprise of numerous characteristic are detected and classified by using spectrogram, Gabor transform and S-transform. The rulebased classifier and the threshold settings of the analysis are according to the IEEE Standard 1159 2009. The best TFD for harmonic signals detection and classification is selected through performance analysis with regards to the accuracy, computational complexity and memory size that been used during the analysis.
Peak detection using wavelet transformIJCNCJournal
A new work based-wavelet transform is designed to overcome one of the main drawbacks that found in the
present new technologies. Orthogonal Frequency Division Multiplexing (OFDM)is proposed in the
literature to enhance the multimedia resolution. However, the high peak power (PAPR) values will obstruct
such achievements. Therefore, a new proposition is found in this work, making use of the wavelet
transforms methods, and it is divided into three main stages; de-noising stage, thresholding stage and then
the replacement stage.
In order to check the system stages validity; a mathematical model has been built and its checked after
using a MATLAB simulation. A simulated bit error rate (BER) achievement will be compared with our
previously published work, where an enhancement from 8×10-1 to be 5×10-1 is achieved. Moreover, these
results will be compared to the work found in the literature, where we have accomplished around 27%
PAPR extra reduction.
As a result, the BER performance has been improved for the same bandwidth occupancy. Moreover and
due to the de-noise stage, the verification rate has been improved to reach 81%. This is in addition to the
noise immunity enhancement.
This paper discusses the time-frequency transform based fault detection and classification of STATCOM (Static synchronous compensator) integrated single circuit transmission line. Here, fast-discrete S-Transform (FDST) based time-frequency transformation is proposed for evaluation of fault detection and classification including STATCOM in transmission line. The STATCOM is placed at mid-point of transmission line. The system starts processing by extracting the current signals from both end of current transformer (CT) connected in transmission line. The current signals from CT’s are fed to FDST to compute the spectral energy (SE) of phase current at both end of the line. The differential spectral energy (DSE) is evaluated by subtracting the SE obtained from sending end and SE obtained from receiving end of the line. The DSE is the key indicator for deciding the fault pattern detection and classification of transmission line. This proposed scheme is simulated using MATLAB simulink R2010a version and successfully tested under various parameter condition such as fault resistance (Rf),source impedance (SI), fault inception angle (FIA) and reverse flow of current. The proposed approach is simple, reliable and efficient as the processing speed is very fast to detect the fault within a cycle period of FDT (fault detection time).
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—
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
Design and verification of pipelined parallel architecture implementation in ...eSAT Publishing House
IJRET : International Journal of Research in Engineering and Technology is an international peer reviewed, online journal published by eSAT Publishing House for the enhancement of research in various disciplines of Engineering and Technology. The aim and scope of the journal is to provide an academic medium and an important reference for the advancement and dissemination of research results that support high-level learning, teaching and research in the fields of Engineering and Technology. We bring together Scientists, Academician, Field Engineers, Scholars and Students of related fields of Engineering and Technology
In the era of technological advancement, use of computer technology has become inevitable. Hence it has become the need of the hour to integrate software methods in engineering curriculum as a part to boost pedagogy techniques. Simulations software is a great help to graduates of disciplines such as electrical engineering. Since electrical engineering deals with high voltages and heavy instruments, extra care must be taken while operating with them. The viable solution would be to have appropriate control. The appropriate control could be well designed if engineers haveknowledge of kind of waveforms associated with the system. Though these waveforms can be plotted manually, but it consumes a lot of time. Hence aid of simulation helps to understand steady state of system and resulting in better performance. In this paper computer, aided teaching of transformer is carried out using MATLAB/Simulink. The test carried out on a transformer includes open circuit test and short circuit respectively. The respective parameters of the transformer are then calculated using the values obtained from the open circuit and short circuit test respectively using Simulink.
This paper describes the steady-state response and control of power in transmission line equipped with
FACTS devices. Detailed simulations are carried out on two -machine systems to illustrate the control
features of these devices and their influence to increase power transfer capability and improve
system reliability. The DPFC is derived from the unified power-flow controller (UPFC) and DPFC
has the same control capability as the UPFC. The DPFC can be considered as a UPFC with an eliminated
common dc link. 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.
The interaction between the DPFC, the network and the machines are analyzed.
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.
Design of CW THz Photonic Transmitter based on Low Pass-Filter and Bow-tie W...IJECEIAES
This paper presents the design of Continuous Wave Terahertz photonic transmitters which is composed from photodetector (PD) associated to a wideband antenna, low–pass filter (LPF) and DC Probe. Firstly, we have developed the bow-tie wideband antenna using an EM solver Momentum integrated in ADS “Advanced Design System”. Then we had optimized a low-pass filter which is responsible of blocking the RF signal providing from the antenna to reach the DC probe. And finally, we have validated into simulation the CW THz photonic transmitter. The three structures are based on multi-layers GaAs substrate, which is the most widely used for THz circuit design. The dimensions of the Whole circuit are 776.788 × 303.39 .
WAVELET- FUZZY BASED MULTI TERMINAL TRANSMISSION SYSTEM PROTECTION SCHEME IN ...ijfls
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.
Adaptive resources assignment in OFDM-based cognitive radio systemsIJECEIAES
Spectrum efficiency of orthogonal frequency division multiplexing (OFDM)-based cognitive radio (CR) systems can be improved by adaptive resources allocation. In resources allocation, transmission resources such as modulation level and transmission power are adaptively assigned based on channel variations. The goal of this paper is maximize the total transmission rate of secondary user (SU). Hence, we investigate adaptive power and modulation allocation to achieve this purpose. For power allocation, we investigate optimal and conventional methods and then introduce a novel suboptimal algorithm to calculate the transmission power of each subcarrier. In addition, for adaptive modulation, we consider two kinds of modulations including multi-quadrature amplitude modulation (MQAM) and multi-phase-shift keying (MPSK). Also, simulation results are indicated the performance of our algorithm.
An Identification of Multiple Harmonic Sources in a Distribution System by Us...journalBEEI
The identification of multiple harmonic sources (MHS) is vital to identify the root causes and the mitigation technique for a harmonic disturbance. This paper introduces an identification technique of MHS in a power distribution system by using a time-frequency distribution (TFD) analysis known as a spectrogram. The spectrogram has advantages in term of its accuracy, a less complex algorithm, and use of low memory size compared to previous methods such as probabilistic and harmonic power flow direction. The identification of MHS is based on the significant relationship of spectral impedances, which are the fundamental impedance (Z1) and harmonic impedance (Zh) that estimate the time-frequency representation (TFR). To verify the performance of the proposed method, an IEEE test feeder with several different harmonic producing loads is simulated. It is shown that the suggested method is excellent with 100% correct identification of MHS. The method is accurate, fast and cost-efficient in the identification of MHS in power distribution arrangement.
Differential equation fault location algorithm with harmonic effects in power...TELKOMNIKA JOURNAL
About 80% of faults in the power system distribution are earth faults. Studies to find effective methods to identify and locate faults in distribution networks are still relevant, in addition to the presence of harmonic signals that distort waves and create deviations in the power system that can cause many problems to the protection relay. This study focuses on a single line-to-ground (SLG) fault location algorithm in a power system distribution network based on fundamental frequency measured using the differential equation method. The developed algorithm considers the presence of harmonics components in the simulation network. In this study, several filters were tested to obtain the lowest fault location error to reduce the effect of harmonic components on the developed fault location algorithm. The network model is simulated using the alternate transients program (ATP)Draw simulation program. Several fault scenarios have been implemented during the simulation, such as fault resistance, fault distance, and fault inception angle. The final results show that the proposed algorithm can estimate the fault distance successfully with an acceptable fault location error. Based on the simulation results, the differential equation continuous wavelet technique (CWT) filter-based algorithm produced an accurate fault location result with a mean average error (MAE) of less than 5%.
An Improved Detection and Classification Technique of Harmonic Signals in Pow...IJECEIAES
This paper introduces an improved detection and classification technique of harmonic signals in power distribution using time-frequency distribution (TFD) analysis which is spectrogram. The spectrogram is an appropriate approach to signify signals in jointly time-frequency domain and known as time frequency representation (TFR). The spectral information of signals can be observed and estimated plainly from TFR due to identify the characteristics of the signals. Based on rule-based classifier and the threshold settings that referred to IEEE Standard 1159 2009, the detection and classification of harmonic signals for 100 unique signals consist of various characteristic of harmonics are carried out successfully. The accuracy of proposed method is examined by using MAPE and the result show that the technique provides high accuracy. In addition, spectrogram also gives 100 percent correct classification of harmonic signals. It is proven that the proposed method is accurate, fast and cost efficient for detecting and classifying harmonic signals in distribution system.
A verification of periodogram technique for harmonic source diagnostic analyt...TELKOMNIKA JOURNAL
A harmonic source diagnostic analytic is vital to identify the root causes and type of harmonic source in power system. This paper introduces a verification of periodogram technique to diagnose harmonic sources by using logistic regression classifier. A periodogram gives a correct and accurate classification of harmonic signals. Signature recognition pattern is used to distinguish the harmonic sources accurately by obtaining the distribution of harmonic and interharmonic components and the harmonic contribution changes. This is achieved by using the significant signature recognition of harmonic producing load obtained from the harmonic contribution changes. To verify the performance of the propose method, a logistic regression classifier will analyse the result and give the accuracy and positive rate percentage of the propose method. The adequacy of the proposed methodology is tested and verified on distribution system for several rectifier and inverter-based loads.
This paper discusses the time-frequency transform based fault detection and classification of STATCOM (Static synchronous compensator) integrated single circuit transmission line. Here, fast-discrete S-Transform (FDST) based time-frequency transformation is proposed for evaluation of fault detection and classification including STATCOM in transmission line. The STATCOM is placed at mid-point of transmission line. The system starts processing by extracting the current signals from both end of current transformer (CT) connected in transmission line. The current signals from CT’s are fed to FDST to compute the spectral energy (SE) of phase current at both end of the line. The differential spectral energy (DSE) is evaluated by subtracting the SE obtained from sending end and SE obtained from receiving end of the line. The DSE is the key indicator for deciding the fault pattern detection and classification of transmission line. This proposed scheme is simulated using MATLAB simulink R2010a version and successfully tested under various parameter condition such as fault resistance (Rf),source impedance (SI), fault inception angle (FIA) and reverse flow of current. The proposed approach is simple, reliable and efficient as the processing speed is very fast to detect the fault within a cycle period of FDT (fault detection time).
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—
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
Design and verification of pipelined parallel architecture implementation in ...eSAT Publishing House
IJRET : International Journal of Research in Engineering and Technology is an international peer reviewed, online journal published by eSAT Publishing House for the enhancement of research in various disciplines of Engineering and Technology. The aim and scope of the journal is to provide an academic medium and an important reference for the advancement and dissemination of research results that support high-level learning, teaching and research in the fields of Engineering and Technology. We bring together Scientists, Academician, Field Engineers, Scholars and Students of related fields of Engineering and Technology
In the era of technological advancement, use of computer technology has become inevitable. Hence it has become the need of the hour to integrate software methods in engineering curriculum as a part to boost pedagogy techniques. Simulations software is a great help to graduates of disciplines such as electrical engineering. Since electrical engineering deals with high voltages and heavy instruments, extra care must be taken while operating with them. The viable solution would be to have appropriate control. The appropriate control could be well designed if engineers haveknowledge of kind of waveforms associated with the system. Though these waveforms can be plotted manually, but it consumes a lot of time. Hence aid of simulation helps to understand steady state of system and resulting in better performance. In this paper computer, aided teaching of transformer is carried out using MATLAB/Simulink. The test carried out on a transformer includes open circuit test and short circuit respectively. The respective parameters of the transformer are then calculated using the values obtained from the open circuit and short circuit test respectively using Simulink.
This paper describes the steady-state response and control of power in transmission line equipped with
FACTS devices. Detailed simulations are carried out on two -machine systems to illustrate the control
features of these devices and their influence to increase power transfer capability and improve
system reliability. The DPFC is derived from the unified power-flow controller (UPFC) and DPFC
has the same control capability as the UPFC. The DPFC can be considered as a UPFC with an eliminated
common dc link. 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.
The interaction between the DPFC, the network and the machines are analyzed.
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.
Design of CW THz Photonic Transmitter based on Low Pass-Filter and Bow-tie W...IJECEIAES
This paper presents the design of Continuous Wave Terahertz photonic transmitters which is composed from photodetector (PD) associated to a wideband antenna, low–pass filter (LPF) and DC Probe. Firstly, we have developed the bow-tie wideband antenna using an EM solver Momentum integrated in ADS “Advanced Design System”. Then we had optimized a low-pass filter which is responsible of blocking the RF signal providing from the antenna to reach the DC probe. And finally, we have validated into simulation the CW THz photonic transmitter. The three structures are based on multi-layers GaAs substrate, which is the most widely used for THz circuit design. The dimensions of the Whole circuit are 776.788 × 303.39 .
WAVELET- FUZZY BASED MULTI TERMINAL TRANSMISSION SYSTEM PROTECTION SCHEME IN ...ijfls
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.
Adaptive resources assignment in OFDM-based cognitive radio systemsIJECEIAES
Spectrum efficiency of orthogonal frequency division multiplexing (OFDM)-based cognitive radio (CR) systems can be improved by adaptive resources allocation. In resources allocation, transmission resources such as modulation level and transmission power are adaptively assigned based on channel variations. The goal of this paper is maximize the total transmission rate of secondary user (SU). Hence, we investigate adaptive power and modulation allocation to achieve this purpose. For power allocation, we investigate optimal and conventional methods and then introduce a novel suboptimal algorithm to calculate the transmission power of each subcarrier. In addition, for adaptive modulation, we consider two kinds of modulations including multi-quadrature amplitude modulation (MQAM) and multi-phase-shift keying (MPSK). Also, simulation results are indicated the performance of our algorithm.
An Identification of Multiple Harmonic Sources in a Distribution System by Us...journalBEEI
The identification of multiple harmonic sources (MHS) is vital to identify the root causes and the mitigation technique for a harmonic disturbance. This paper introduces an identification technique of MHS in a power distribution system by using a time-frequency distribution (TFD) analysis known as a spectrogram. The spectrogram has advantages in term of its accuracy, a less complex algorithm, and use of low memory size compared to previous methods such as probabilistic and harmonic power flow direction. The identification of MHS is based on the significant relationship of spectral impedances, which are the fundamental impedance (Z1) and harmonic impedance (Zh) that estimate the time-frequency representation (TFR). To verify the performance of the proposed method, an IEEE test feeder with several different harmonic producing loads is simulated. It is shown that the suggested method is excellent with 100% correct identification of MHS. The method is accurate, fast and cost-efficient in the identification of MHS in power distribution arrangement.
Differential equation fault location algorithm with harmonic effects in power...TELKOMNIKA JOURNAL
About 80% of faults in the power system distribution are earth faults. Studies to find effective methods to identify and locate faults in distribution networks are still relevant, in addition to the presence of harmonic signals that distort waves and create deviations in the power system that can cause many problems to the protection relay. This study focuses on a single line-to-ground (SLG) fault location algorithm in a power system distribution network based on fundamental frequency measured using the differential equation method. The developed algorithm considers the presence of harmonics components in the simulation network. In this study, several filters were tested to obtain the lowest fault location error to reduce the effect of harmonic components on the developed fault location algorithm. The network model is simulated using the alternate transients program (ATP)Draw simulation program. Several fault scenarios have been implemented during the simulation, such as fault resistance, fault distance, and fault inception angle. The final results show that the proposed algorithm can estimate the fault distance successfully with an acceptable fault location error. Based on the simulation results, the differential equation continuous wavelet technique (CWT) filter-based algorithm produced an accurate fault location result with a mean average error (MAE) of less than 5%.
An Improved Detection and Classification Technique of Harmonic Signals in Pow...IJECEIAES
This paper introduces an improved detection and classification technique of harmonic signals in power distribution using time-frequency distribution (TFD) analysis which is spectrogram. The spectrogram is an appropriate approach to signify signals in jointly time-frequency domain and known as time frequency representation (TFR). The spectral information of signals can be observed and estimated plainly from TFR due to identify the characteristics of the signals. Based on rule-based classifier and the threshold settings that referred to IEEE Standard 1159 2009, the detection and classification of harmonic signals for 100 unique signals consist of various characteristic of harmonics are carried out successfully. The accuracy of proposed method is examined by using MAPE and the result show that the technique provides high accuracy. In addition, spectrogram also gives 100 percent correct classification of harmonic signals. It is proven that the proposed method is accurate, fast and cost efficient for detecting and classifying harmonic signals in distribution system.
A verification of periodogram technique for harmonic source diagnostic analyt...TELKOMNIKA JOURNAL
A harmonic source diagnostic analytic is vital to identify the root causes and type of harmonic source in power system. This paper introduces a verification of periodogram technique to diagnose harmonic sources by using logistic regression classifier. A periodogram gives a correct and accurate classification of harmonic signals. Signature recognition pattern is used to distinguish the harmonic sources accurately by obtaining the distribution of harmonic and interharmonic components and the harmonic contribution changes. This is achieved by using the significant signature recognition of harmonic producing load obtained from the harmonic contribution changes. To verify the performance of the propose method, a logistic regression classifier will analyse the result and give the accuracy and positive rate percentage of the propose method. The adequacy of the proposed methodology is tested and verified on distribution system for several rectifier and inverter-based loads.
An Accurate Classification Method of Harmonic Signals in Power Distribution S...TELKOMNIKA JOURNAL
This paper presents an accurate classification method of harmonic signal in power distribution
system by using S-transform (ST). ST has a capability of representing signals in jointly time-frequency
domain and known as time frequency representation (TFR). The spectral parameters are estimated from
TFR in order to identify the characteristics and to classify the harmonic signals. The classification of
harmonic signals with the utilization of pattern recognition approach which is rule-based classifier of 100
unique signals is according to the IEEE standard 519:2014. The accuracy of the proposed method is
determined by using MAPE and the results proved that the method provides high accuracy of harmonic
signal classification. Additionally, S-transform also gives 100 percent correct classification of harmonic
signals. It is proven that the proposed method is accurate in detecting and classifying harmonic signals in
the distribution system.
A Utilisation of Improved Gabor Transform for Harmonic Signals Detection and ...IJECEIAES
This paper presents a utilization of improved Gabor transform for harmonic signals detection and classification analysis in power distribution system. The Gabor transform is one of time frequency distribution technique with a capability of representing signals in jointly time-frequency domain and known as time frequency representation (TFR). The estimation of spectral information can be obtained from TFR in order to identify the characteristics of the signals. The detection and classification of harmonic signals for 100 unique signals with numerous characteristic of harmonics with support of rule-based classifier and threshold setting that been referred to IEEE standard 1159 2009. The accuracy of proposed method is determined by using MAPE and the outcome demonstrate that the method gives high accuracy of harmonic signals classification. Additionally, Gabor transform also gives 100 percent correct classification of harmonic signals. It is verified that the proposed method is accurate and cost efficient in detecting and classifying harmonic signals in distribution system.
A Utilisation of Improved Gabor Transform for Harmonic Signals Detection and ...Yayah Zakaria
his paper presents a utilization of improved Gabor transform for harmonic signals detection and classification analysis in power distribution system. The Gabor transform is one of time frequency distribution technique with a capability of representing signals in jointly time-frequency domain and known as time frequency representation (TFR). The estimation of spectral
information can be obtained from TFR in order to identify the characteristics of the signals. The detection and classification of harmonic signals for 10 unique signals with numerous characteristic of harmonics with support of rule-based classifier and threshold setting that been referred to IEEE standard 1159 2009. The accuracy of proposed method is determined by using MAPE and the outcome demonstrate that the method gives high accuracy of harmonic signals classification. Additionally, Gabor transform also gives 100 percent correct classification of harmonic signals. It is verified that the proposed method is accurate and cost efficient in detecting and classifying harmonic signals in distribution system.
An Analysis of Harmonic and Interharmonic Contribution of Electric Arc Furnac...IJECEIAES
Fast and accurate detection of the harmonic and interharmonic contribution of electric arc furnace (EAF) is crucial in identifying and to mitigate the undesired effects to the system. In this paper, periodogram, a fast and accurate technique is introduced for the analysis of the contribution. Based on a rule-based classifier and the threshold settings that referred to the IEEE Standard 1159 2009, the analysis of the harmonic and interharmonic contribution of EAF are carried out successfully. Moreover, the impact of contribution is measured using total harmonic distortion (THD) and total non-harmonic distortion (TnHD). In addition, periodogram also gives 100 percent correct detection and able to analyze the contribution impact. It is proven that the proposed method is accurate, fast and cost efficient for analyzing the impact of harmonic and interharmonic of EAF.
Diagnosis of broken bars fault in induction machines using higher order spect...ISA Interchange
Detection and identification of induction machine faults through the stator current signal using higher order spectra analysis is presented. This technique is known as motor current signature analysis (MCSA). This paper proposes two higher order spectra techniques, namely the power spectrum and the slices of bi-spectrum used for the analysis of induction machine stator current leading to the detection of electrical failures within the rotor cage. The method has been tested by using both healthy and broken rotor bars cases for an 18.5 kW-220 V/380 V-50 Hz-2 pair of poles induction motor under different load conditions. Experimental signals have been analyzed highlighting that bi-spectrum results show their superiority in the accurate detection of rotor broken bars. Even when the induction machine is rotating at a low level of shaft load (no-load condition), the rotor fault detection is efficient. We will also demonstrate through the analysis and experimental verification, that our proposed proposed-method has better detection performance in terms of receiver operation characteristics (ROC) curves and precision-recall graph.
A Fast Localization of Multiple Harmonic Sources for Rectifier Loads by Utili...TELKOMNIKA JOURNAL
This paper introduces a fast method to localize the multiple harmonic sources (MHS) for rectifier
based loads in power distribution system by utilizing periodogram technique with a single-point
measurement approach at the point of common coupling (PCC). The periodogram is a fast and accurate
technique for analyzing and distinguishing MHS location in power system. Matlab simulation is carried out
several unique cases on IEEE test feeder cases due to validate the proposed method. The identification of
MHS location is based on the significant relationship of spectral impedance which are fundamental
impedance (Z1) and harmonic impedance (Zh) that's extracted from an impedance power spectrum. It is
verified that the proposed method is fast, accurate, and cost efficient in localizing MHS. In addition, this
method also contributes 100% correct identification of MHS location.
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.
A simple faulted phase-based fault distance estimation algorithm for a loop d...nooriasukmaningtyas
This paper presents a single ended faulted phase-based traveling wave fault localization algorithm for loop distribution grids which is that the sensor can get many reflected signals from the fault point to face the complexity of localization. This localization algorithm uses a band pass filter to remove noise from the corrupted signal. The arriving times of the faulted phase-based filtered signals can be obtained by using phase-modal and discrete wavelet transformations. The estimated fault distance can be calculated using the traveling wave method. The proposed algorithm presents detail level analysis using three detail levels coefficients. The proposed algorithm is tested with MATLAB simulation single line to ground fault in a 10 kV grounded loop distribution system. The simulation result shows that the faulted phase time delay can give better accuracy than using conventional time delays. The proposed algorithm can give fault distance estimation accuracy up to 99.7% with 30 dB contaminated signal-to-noise ratio (SNR) for the nearest lines from the measured terminal.
A simple faulted phase-based fault distance estimation algorithm for a loop d...IJEECSIAES
This paper presents a single ended faulted phase-based traveling wave fault localization algorithm for loop distribution grids which is that the sensor can
get many reflected signals from the fault point to face the complexity of localization. This localization algorithm uses a band pass filter to remove noise from the corrupted signal. The arriving times of the faulted phasebased filtered signals can be obtained by using phase-modal and discrete
wavelet transformations. The estimated fault distance can be calculated using the traveling wave method. The proposed algorithm presents detail
level analysis using three detail levels coefficients. The proposed algorithm is tested with MATLAB simulation single line to ground fault in a 10 kV grounded loop distribution system. The simulation result shows that the
faulted phase time delay can give better accuracy than using conventional time delays. The proposed algorithm can give fault distance estimation accuracy up to 99.7% with 30 dB contaminated signal-to-noise ratio (SNR)
for the nearest lines from the measured terminal.
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.
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.
Analysis of harmonics and resonances in hvdc mmc link connected to AC gridBérengère VIGNAUX
High-frequency responses of HVDC-MMC links are essential to study because harmonic and resonance phenomena may impact the AC grid. In this paper, EMT-type simulations are used to analyze converter station’s frequency response.
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.
ESPRIT Method Enhancement for Real-time Wind Turbine Fault RecognitionIAES-IJPEDS
Early fault diagnosis plays a very important role in the modern energy production systems. The wind turbine machine requires a regular maintenance to guarantee an acceptable lifetime and to minimize production loss. In order to implement a fast, proactive condition monitoring, ESPRIT- TLS method seems the correct choice due to its robustness in improving the frequency and amplitude detection. Nevertheless, it has a very complex computation to implement in real time. To avoid this problem, a Fast- ESPRIT algorithm that combined the IIR band-pass filtering technique, the decimation technique and the original ESPRIT-TLS method were employed to enhance extracting accurately frequencies and their magnitudes from the wind stator current. The proposed algorithm has been evaluated by computer simulations with many fault scenarios. Study results demonstrate the performance of Fast-ESPRIT allowing fast and high resolution harmonics identification with minimum computation time and less memory cost.
Similar to Accurate harmonic source identification using S-transform (20)
Amazon products reviews classification based on machine learning, deep learni...TELKOMNIKA JOURNAL
In recent times, the trend of online shopping through e-commerce stores and websites has grown to a huge extent. Whenever a product is purchased on an e-commerce platform, people leave their reviews about the product. These reviews are very helpful for the store owners and the product’s manufacturers for the betterment of their work process as well as product quality. An automated system is proposed in this work that operates on two datasets D1 and D2 obtained from Amazon. After certain preprocessing steps, N-gram and word embedding-based features are extracted using term frequency-inverse document frequency (TF-IDF), bag of words (BoW) and global vectors (GloVe), and Word2vec, respectively. Four machine learning (ML) models support vector machines (SVM), logistic regression (RF), logistic regression (LR), multinomial Naïve Bayes (MNB), two deep learning (DL) models convolutional neural network (CNN), long-short term memory (LSTM), and standalone bidirectional encoder representations (BERT) are used to classify reviews as either positive or negative. The results obtained by the standard ML, DL models and BERT are evaluated using certain performance evaluation measures. BERT turns out to be the best-performing model in the case of D1 with an accuracy of 90% on features derived by word embedding models while the CNN provides the best accuracy of 97% upon word embedding features in the case of D2. The proposed model shows better overall performance on D2 as compared to D1.
Design, simulation, and analysis of microstrip patch antenna for wireless app...TELKOMNIKA JOURNAL
In this study, a microstrip patch antenna that works at 3.6 GHz was built and tested to see how well it works. In this work, Rogers RT/Duroid 5880 has been used as the substrate material, with a dielectric permittivity of 2.2 and a thickness of 0.3451 mm; it serves as the base for the examined antenna. The computer simulation technology (CST) studio suite is utilized to show the recommended antenna design. The goal of this study was to get a more extensive transmission capacity, a lower voltage standing wave ratio (VSWR), and a lower return loss, but the main goal was to get a higher gain, directivity, and efficiency. After simulation, the return loss, gain, directivity, bandwidth, and efficiency of the supplied antenna are found to be -17.626 dB, 9.671 dBi, 9.924 dBi, 0.2 GHz, and 97.45%, respectively. Besides, the recreation uncovered that the transfer speed side-lobe level at phi was much better than those of the earlier works, at -28.8 dB, respectively. Thus, it makes a solid contender for remote innovation and more robust communication.
Design and simulation an optimal enhanced PI controller for congestion avoida...TELKOMNIKA JOURNAL
In this paper, snake optimization algorithm (SOA) is used to find the optimal gains of an enhanced controller for controlling congestion problem in computer networks. M-file and Simulink platform is adopted to evaluate the response of the active queue management (AQM) system, a comparison with two classical controllers is done, all tuned gains of controllers are obtained using SOA method and the fitness function chose to monitor the system performance is the integral time absolute error (ITAE). Transient analysis and robust analysis is used to show the proposed controller performance, two robustness tests are applied to the AQM system, one is done by varying the size of queue value in different period and the other test is done by changing the number of transmission control protocol (TCP) sessions with a value of ± 20% from its original value. The simulation results reflect a stable and robust behavior and best performance is appeared clearly to achieve the desired queue size without any noise or any transmission problems.
Improving the detection of intrusion in vehicular ad-hoc networks with modifi...TELKOMNIKA JOURNAL
Vehicular ad-hoc networks (VANETs) are wireless-equipped vehicles that form networks along the road. The security of this network has been a major challenge. The identity-based cryptosystem (IBC) previously used to secure the networks suffers from membership authentication security features. This paper focuses on improving the detection of intruders in VANETs with a modified identity-based cryptosystem (MIBC). The MIBC is developed using a non-singular elliptic curve with Lagrange interpolation. The public key of vehicles and roadside units on the network are derived from number plates and location identification numbers, respectively. Pseudo-identities are used to mask the real identity of users to preserve their privacy. The membership authentication mechanism ensures that only valid and authenticated members of the network are allowed to join the network. The performance of the MIBC is evaluated using intrusion detection ratio (IDR) and computation time (CT) and then validated with the existing IBC. The result obtained shows that the MIBC recorded an IDR of 99.3% against 94.3% obtained for the existing identity-based cryptosystem (EIBC) for 140 unregistered vehicles attempting to intrude on the network. The MIBC shows lower CT values of 1.17 ms against 1.70 ms for EIBC. The MIBC can be used to improve the security of VANETs.
Conceptual model of internet banking adoption with perceived risk and trust f...TELKOMNIKA JOURNAL
Understanding the primary factors of internet banking (IB) acceptance is critical for both banks and users; nevertheless, our knowledge of the role of users’ perceived risk and trust in IB adoption is limited. As a result, we develop a conceptual model by incorporating perceived risk and trust into the technology acceptance model (TAM) theory toward the IB. The proper research emphasized that the most essential component in explaining IB adoption behavior is behavioral intention to use IB adoption. TAM is helpful for figuring out how elements that affect IB adoption are connected to one another. According to previous literature on IB and the use of such technology in Iraq, one has to choose a theoretical foundation that may justify the acceptance of IB from the customer’s perspective. The conceptual model was therefore constructed using the TAM as a foundation. Furthermore, perceived risk and trust were added to the TAM dimensions as external factors. The key objective of this work was to extend the TAM to construct a conceptual model for IB adoption and to get sufficient theoretical support from the existing literature for the essential elements and their relationships in order to unearth new insights about factors responsible for IB adoption.
Efficient combined fuzzy logic and LMS algorithm for smart antennaTELKOMNIKA JOURNAL
The smart antennas are broadly used in wireless communication. The least mean square (LMS) algorithm is a procedure that is concerned in controlling the smart antenna pattern to accommodate specified requirements such as steering the beam toward the desired signal, in addition to placing the deep nulls in the direction of unwanted signals. The conventional LMS (C-LMS) has some drawbacks like slow convergence speed besides high steady state fluctuation error. To overcome these shortcomings, the present paper adopts an adaptive fuzzy control step size least mean square (FC-LMS) algorithm to adjust its step size. Computer simulation outcomes illustrate that the given model has fast convergence rate as well as low mean square error steady state.
Design and implementation of a LoRa-based system for warning of forest fireTELKOMNIKA JOURNAL
This paper presents the design and implementation of a forest fire monitoring and warning system based on long range (LoRa) technology, a novel ultra-low power consumption and long-range wireless communication technology for remote sensing applications. The proposed system includes a wireless sensor network that records environmental parameters such as temperature, humidity, wind speed, and carbon dioxide (CO2) concentration in the air, as well as taking infrared photos.The data collected at each sensor node will be transmitted to the gateway via LoRa wireless transmission. Data will be collected, processed, and uploaded to a cloud database at the gateway. An Android smartphone application that allows anyone to easily view the recorded data has been developed. When a fire is detected, the system will sound a siren and send a warning message to the responsible personnel, instructing them to take appropriate action. Experiments in Tram Chim Park, Vietnam, have been conducted to verify and evaluate the operation of the system.
Wavelet-based sensing technique in cognitive radio networkTELKOMNIKA JOURNAL
Cognitive radio is a smart radio that can change its transmitter parameter based on interaction with the environment in which it operates. The demand for frequency spectrum is growing due to a big data issue as many Internet of Things (IoT) devices are in the network. Based on previous research, most frequency spectrum was used, but some spectrums were not used, called spectrum hole. Energy detection is one of the spectrum sensing methods that has been frequently used since it is easy to use and does not require license users to have any prior signal understanding. But this technique is incapable of detecting at low signal-to-noise ratio (SNR) levels. Therefore, the wavelet-based sensing is proposed to overcome this issue and detect spectrum holes. The main objective of this work is to evaluate the performance of wavelet-based sensing and compare it with the energy detection technique. The findings show that the percentage of detection in wavelet-based sensing is 83% higher than energy detection performance. This result indicates that the wavelet-based sensing has higher precision in detection and the interference towards primary user can be decreased.
A novel compact dual-band bandstop filter with enhanced rejection bandsTELKOMNIKA JOURNAL
In this paper, we present the design of a new wide dual-band bandstop filter (DBBSF) using nonuniform transmission lines. The method used to design this filter is to replace conventional uniform transmission lines with nonuniform lines governed by a truncated Fourier series. Based on how impedances are profiled in the proposed DBBSF structure, the fractional bandwidths of the two 10 dB-down rejection bands are widened to 39.72% and 52.63%, respectively, and the physical size has been reduced compared to that of the filter with the uniform transmission lines. The results of the electromagnetic (EM) simulation support the obtained analytical response and show an improved frequency behavior.
Deep learning approach to DDoS attack with imbalanced data at the application...TELKOMNIKA JOURNAL
A distributed denial of service (DDoS) attack is where one or more computers attack or target a server computer, by flooding internet traffic to the server. As a result, the server cannot be accessed by legitimate users. A result of this attack causes enormous losses for a company because it can reduce the level of user trust, and reduce the company’s reputation to lose customers due to downtime. One of the services at the application layer that can be accessed by users is a web-based lightweight directory access protocol (LDAP) service that can provide safe and easy services to access directory applications. We used a deep learning approach to detect DDoS attacks on the CICDDoS 2019 dataset on a complex computer network at the application layer to get fast and accurate results for dealing with unbalanced data. Based on the results obtained, it is observed that DDoS attack detection using a deep learning approach on imbalanced data performs better when implemented using synthetic minority oversampling technique (SMOTE) method for binary classes. On the other hand, the proposed deep learning approach performs better for detecting DDoS attacks in multiclass when implemented using the adaptive synthetic (ADASYN) method.
The appearance of uncertainties and disturbances often effects the characteristics of either linear or nonlinear systems. Plus, the stabilization process may be deteriorated thus incurring a catastrophic effect to the system performance. As such, this manuscript addresses the concept of matching condition for the systems that are suffering from miss-match uncertainties and exogeneous disturbances. The perturbation towards the system at hand is assumed to be known and unbounded. To reach this outcome, uncertainties and their classifications are reviewed thoroughly. The structural matching condition is proposed and tabulated in the proposition 1. Two types of mathematical expressions are presented to distinguish the system with matched uncertainty and the system with miss-matched uncertainty. Lastly, two-dimensional numerical expressions are provided to practice the proposed proposition. The outcome shows that matching condition has the ability to change the system to a design-friendly model for asymptotic stabilization.
Implementation of FinFET technology based low power 4×4 Wallace tree multipli...TELKOMNIKA JOURNAL
Many systems, including digital signal processors, finite impulse response (FIR) filters, application-specific integrated circuits, and microprocessors, use multipliers. The demand for low power multipliers is gradually rising day by day in the current technological trend. In this study, we describe a 4×4 Wallace multiplier based on a carry select adder (CSA) that uses less power and has a better power delay product than existing multipliers. HSPICE tool at 16 nm technology is used to simulate the results. In comparison to the traditional CSA-based multiplier, which has a power consumption of 1.7 µW and power delay product (PDP) of 57.3 fJ, the results demonstrate that the Wallace multiplier design employing CSA with first zero finding logic (FZF) logic has the lowest power consumption of 1.4 µW and PDP of 27.5 fJ.
Evaluation of the weighted-overlap add model with massive MIMO in a 5G systemTELKOMNIKA JOURNAL
The flaw in 5G orthogonal frequency division multiplexing (OFDM) becomes apparent in high-speed situations. Because the doppler effect causes frequency shifts, the orthogonality of OFDM subcarriers is broken, lowering both their bit error rate (BER) and throughput output. As part of this research, we use a novel design that combines massive multiple input multiple output (MIMO) and weighted overlap and add (WOLA) to improve the performance of 5G systems. To determine which design is superior, throughput and BER are calculated for both the proposed design and OFDM. The results of the improved system show a massive improvement in performance ver the conventional system and significant improvements with massive MIMO, including the best throughput and BER. When compared to conventional systems, the improved system has a throughput that is around 22% higher and the best performance in terms of BER, but it still has around 25% less error than OFDM.
Reflector antenna design in different frequencies using frequency selective s...TELKOMNIKA JOURNAL
In this study, it is aimed to obtain two different asymmetric radiation patterns obtained from antennas in the shape of the cross-section of a parabolic reflector (fan blade type antennas) and antennas with cosecant-square radiation characteristics at two different frequencies from a single antenna. For this purpose, firstly, a fan blade type antenna design will be made, and then the reflective surface of this antenna will be completed to the shape of the reflective surface of the antenna with the cosecant-square radiation characteristic with the frequency selective surface designed to provide the characteristics suitable for the purpose. The frequency selective surface designed and it provides the perfect transmission as possible at 4 GHz operating frequency, while it will act as a band-quenching filter for electromagnetic waves at 5 GHz operating frequency and will be a reflective surface. Thanks to this frequency selective surface to be used as a reflective surface in the antenna, a fan blade type radiation characteristic at 4 GHz operating frequency will be obtained, while a cosecant-square radiation characteristic at 5 GHz operating frequency will be obtained.
Reagentless iron detection in water based on unclad fiber optical sensorTELKOMNIKA JOURNAL
A simple and low-cost fiber based optical sensor for iron detection is demonstrated in this paper. The sensor head consist of an unclad optical fiber with the unclad length of 1 cm and it has a straight structure. Results obtained shows a linear relationship between the output light intensity and iron concentration, illustrating the functionality of this iron optical sensor. Based on the experimental results, the sensitivity and linearity are achieved at 0.0328/ppm and 0.9824 respectively at the wavelength of 690 nm. With the same wavelength, other performance parameters are also studied. Resolution and limit of detection (LOD) are found to be 0.3049 ppm and 0.0755 ppm correspondingly. This iron sensor is advantageous in that it does not require any reagent for detection, enabling it to be simpler and cost-effective in the implementation of the iron sensing.
Impact of CuS counter electrode calcination temperature on quantum dot sensit...TELKOMNIKA JOURNAL
In place of the commercial Pt electrode used in quantum sensitized solar cells, the low-cost CuS cathode is created using electrophoresis. High resolution scanning electron microscopy and X-ray diffraction were used to analyze the structure and morphology of structural cubic samples with diameters ranging from 40 nm to 200 nm. The conversion efficiency of solar cells is significantly impacted by the calcination temperatures of cathodes at 100 °C, 120 °C, 150 °C, and 180 °C under vacuum. The fluorine doped tin oxide (FTO)/CuS cathode electrode reached a maximum efficiency of 3.89% when it was calcined at 120 °C. Compared to other temperature combinations, CuS nanoparticles crystallize at 120 °C, which lowers resistance while increasing electron lifetime.
In place of the commercial Pt electrode used in quantum sensitized solar cells, the low-cost CuS cathode is created using electrophoresis. High resolution scanning electron microscopy and X-ray diffraction were used to analyze the structure and morphology of structural cubic samples with diameters ranging from 40 nm to 200 nm. The conversion efficiency of solar cells is significantly impacted by the calcination temperatures of cathodes at 100 °C, 120 °C, 150 °C, and 180 °C under vacuum. The fluorine doped tin oxide (FTO)/CuS cathode electrode reached a maximum efficiency of 3.89% when it was calcined at 120 °C. Compared to other temperature combinations, CuS nanoparticles crystallize at 120 °C, which lowers resistance while increasing electron lifetime.
A progressive learning for structural tolerance online sequential extreme lea...TELKOMNIKA JOURNAL
This article discusses the progressive learning for structural tolerance online sequential extreme learning machine (PSTOS-ELM). PSTOS-ELM can save robust accuracy while updating the new data and the new class data on the online training situation. The robustness accuracy arises from using the householder block exact QR decomposition recursive least squares (HBQRD-RLS) of the PSTOS-ELM. This method is suitable for applications that have data streaming and often have new class data. Our experiment compares the PSTOS-ELM accuracy and accuracy robustness while data is updating with the batch-extreme learning machine (ELM) and structural tolerance online sequential extreme learning machine (STOS-ELM) that both must retrain the data in a new class data case. The experimental results show that PSTOS-ELM has accuracy and robustness comparable to ELM and STOS-ELM while also can update new class data immediately.
Electroencephalography-based brain-computer interface using neural networksTELKOMNIKA JOURNAL
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Accurate harmonic source identification using S-transform
1. TELKOMNIKA Telecommunication, Computing, Electronics and Control
Vol. 18, No. 5, October 2020, pp. 2708~2717
ISSN: 1693-6930, accredited First Grade by Kemenristekdikti, Decree No: 21/E/KPT/2018
DOI: 10.12928/TELKOMNIKA.v18i5.5632 2708
Journal homepage: http://journal.uad.ac.id/index.php/TELKOMNIKA
Accurate harmonic source identification using S-transform
Mohd Hatta Jopri1
, Abdul Rahim Abdullah2
, Rony Karim3
,
Srete Nikolovski4
, Tole Sutikno5
, Mustafa Manap6
1,6
Faculty of Electrical and Electronic Engineering Technology, Universiti Teknikal Malaysia Melaka, Malaysia
2
Faculty of Electrical Engineering, Universiti Teknikal Malaysia Melaka, Malaysia
3
Infineon Technologies AG, Germany
4
Department of Power System, Faculty of Electrical Engineering, University of Osijek, Croatia
5
Deparment of Electrical Engineering, Universitas Ahmad Dahlan, Indonesia
Article Info ABSTRACT
Article history:
Received Jan 15, 2020
Revised Apr 16, 2020
Accepted May 1, 2020
This paper introduces the accurate identification of harmonic sources in
the power distribution system using time-frequency distribution (TFD)
analysis, which is S-transform. The S-transform is a very applicable method
to represent signals parameters in time-frequency representation (TFR) such
as TFR impedance (ZTFR) and the main advantages of S-transform it
can provide better frequency resolution for low frequency components and
also offers better time resolution for high-frequency components.
The identification of multiple harmonic sources are based on the significant
relationship of spectral impedances (ZS) that extracted from the ZTFR, consist
of the fundamental impedance (Z1) and harmonic impedance (Zh). To verify
the accuracy of the proposed method, MATLAB simulations carried out
several unique cases on IEEE 4-bus test feeder cases. It is proven that
the proposed method is superior, with 100% correct identification of harmonic
source location. It is proven that the method is accurate, fast and cost-efficient
to localize harmonic sources in the power distribution system.
Keywords:
Harmonic source identification
Power distribution system
Spectral impedance
S-transform
Time-frequency distribution
This is an open access article under the CC BY-SA license.
Corresponding Author:
Mohd Hatta Jopri,
Faculty of Electrical and Electronic Engineering Technology,
Universiti Teknikal Malaysia Melaka (UTeM),
Hang Tuah Jaya St., 76100 Durian Tunggal, Melaka, Malaysia.
Email: hatta@utem.edu.my
1. INTRODUCTION
As the power quality (PQ) issues caused mainly by harmonics directly affect the overall continuation
of electric transmission and distribution network, the uninterrupted monitoring of electric power systems
(EPSs) has become highly necessary for the utility industry [1, 2]. The harmonic distortion causes several
adverse effects such as overheating of rotational machines, static machines, and current‐carrying conductors.
Furthermore, it causes premature breakdown or action of protecting appliances and harmonic resonance
situations on the customers' EPS and metering imprecisions [2, 3].
In EPS, multiple harmonic sources can be found at the utility side, which known as upstream and
downstream when harmonic sources located at the customer side with respect to a measurement point of point
of common coupling (PCC) [4, 5]. Previously, numerous of harmonic source identification can be found in
many kinds of literature. The earliest technique to localize the harmonic sources is utilizing power direction
technique. However, this method used limited harmonic power-based indices, whereas mathematical analysis
has shown the power direction method is not suitable for harmonic source detection [6, 7]. Furthermore, a state
2. TELKOMNIKA Telecommun Comput El Control
Accurate harmonic source identification using S-transform (Mohd Hatta Jopri)
2709
estimation method is presented with the accomplishment of least square and Kirchhoff current law [8]. Yet,
a study from [9], explained that the state estimation technique requires numerous measurement devices and
unreasonable setup cost for the large power system. Thus, to overcome the previous constraint, the critical
impedance method is introduced [10, 11]. The main disadvantage of this method is to know the value of source
internal impedances of customer and utility, whereas it is difficult to obtain these parameters without switching
tests [12, 13]. Consequently, a harmonic current vector method is introduced due to solving the previous
method drawback. However, the measurement long-drawn-out and hard to analyze harmonic impedances at
the customer side [14-16].
In the previous studies [17-20], the harmonic source estimation is discussed by applying the Bayesian
estimation and harmonic state estimation (HSE). Unfortunately, this technique involves high computational
complexity and the set-up cost of the distributed measurement system station is very expensive [5, 21, 22].
In real-time, accuracy, fast analysis and low cost are essential. Therefore, the limitation of previous analysis
techniques can be solved by using signal processing techniques such as fast fourier transform (FFT),
spectrogram and S-transform [2].
A harmonic source identification using FFT is introduced to provide fast analysis in determining the
location of harmonic sources in the EPS. The significant relationship of spectral impedance, which are
fundamental and harmonic impedance are used due to identify the harmonic location of the harmonic
source [23, 24]. However, the drawback of the FFT technique, such as the signal information, for instance,
amplitude frequencies and phases, cannot be acquired correctly. This is because of the leakage, aliasing effects,
and picket fence formed by the FFT [25-27]. As a result of the FFT limitation, the spectrogram is presented to
identify the harmonic source location [28]. Conversely, the spectrogram has two main disadvantages. First, its
time-frequency resolution is limited by Heisenberg’s Uncertainty Principle. Secondly, both its energy location
in the time-frequency representation and its resolution can vary with the window selected [29-32].
The S-transform is the advancement of wavelet transform (WT) and short-time fourier transform
(STFT) by its variable window and phase correction, respectively. Similar to WT, it offers an improved time
and frequency representation of a signal. Additionally, the scalable and movable Gaussian window properties
of the ST can be utilized for superior recognition of any power quality events [2, 33-35]. Due to the excellent
features of the S-transform in power quality analysis, it is a necessity to perform an analysis of identifying the
location of the harmonic sources using this technique. In this paper, the S-transform is proposed to identify the
location of the harmonic source in the distribution system with a single-point measurement approach at the point
of common coupling (PCC). S-transform is a technique that uses time-frequency analysis to distinguish the signals
in time and frequency representation (TFR) [36, 37]. The S-transform is proposed because it is able to provide
provides better frequency resolution for low-frequency components and also offers better time resolution for high-
frequency components.
2. PROPOSED METHOD
Harmonic current source type-load is selected as a frequent and widely use of harmonic producing
loads in industrial [38, 39]. A time-frequency analysis which is used in this research is the S-transform. Three
steps are proposed in this method. Firstly, measurement of voltage and current at the PCC. Secondly, these
signals are analyzed using S-transform due to obtain the signal parameters in time-frequency representation
(TFR) plane. Thirdly, the spectral impedance components are extracted from the TFR impedance and
the significant relationship of these components are used in identifying the harmonic source location.
2.1. S-transform
S-transform combines the element of wavelet transform (WT) and the short-time fourier transform
(STFT), which inherits the advantage of WT and STFT in signal processing. In particular, ST employs
a moving and scalable localizing Gaussian window in the transformation process. The Gaussian window is
as shown in (2). Mathematically ST can be defined as [29],
𝑆𝑇(𝜏, 𝑓) = ∫ 𝑥(𝑡)
|𝑓|
√2𝜋
𝑒
−(𝜏−𝑡)2 𝑓2
2 𝑒−𝑗2𝜋𝑓𝑡
𝑑𝑡
∞
−∞
(1)
𝑔(𝑡) =
1
𝜎√2𝜋
𝑒
−𝑡2
2𝜎2
(2)
𝜎(𝑓) =
1
|𝑓|
(3)
where 𝑥(𝑡) is the signal, 𝑡 is the time, 𝑓 is the frequency, 𝑔(𝑡) is the scalable Gaussian window, and 𝜎(𝑓) is
a parameter that controls the position of the Gaussian window.
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2.2. Signal parameters
The parameters of power quality signals are extracted from the TFR to provide the information of
the signal in time.
2.2.1. Instantaneous total non-harmonic distortion
Total harmonic distortion, THD, is used to measure of how much harmonic content in
a waveform [40]. The instantaneous total harmonic distortion of a waveform is defined mathematically as (4),
𝑇𝐻𝐷(𝑡) =
√∑ 𝑉ℎ,𝑟𝑚𝑠(𝑡)2𝐻
ℎ=2
𝑉1𝑟𝑚𝑠(𝑡)
(4)
where Vh,rms(t) is RMS harmonic voltage and Vh,rms(t) is RMS fundamental voltage. The instantaneous total
harmonic distortion of a waveform is defined mathematically as.
2.2.2. Instantaneous total non-harmonic distortion
Besides harmonic, a signal also contains interharmonic components that are not multiple integers of
the power system frequency [27]. Referring to this as the instantaneous total nonharmonic distortion,
(TnHD(t)), then for this parameter is written as (5).
𝑇𝑛𝐻𝐷(𝑡) =
√𝑉𝑟𝑚𝑠(𝑡)2−∑ 𝑉ℎ,𝑟𝑚𝑠(𝑡)2𝐻
ℎ=0
𝑉1𝑟𝑚𝑠(𝑡)
(5)
2.3. Spectral impedance
The spectral impedance (ZS) components are extracted from the TFR impedance (ZTFR). The ZTFR can be
calculated using equation at each harmonic frequency and the values then plotted. The ZTFR is expressed as (6) [13].
𝑍 𝑇𝐹𝑅 =
𝑆 𝑉(𝑡,𝑓)
𝑆 𝐼(𝑡,𝑓)
(6)
where SV(t,f) is the TFR of voltage and SI(t,f) is the TFR of current. The spectral impedance consists of
a fundamental impedance (Z1), whereas the harmonic impedance (Zh) is a harmonic impedance at the order
number of harmonic.
2.4. Implementation of proposed method
In most recent studies, suggest the execution of the proposed technique can be realized as depicts in
Figure 1 (a) and Figure 1 (b) using IEEE 4-bus test feeders, while the harmonic source is modeled as an
inverter-based load, which is known as harmonic current source type-load [41-43], where N is a linear load,
which is a resistor whereas H is a harmonic source. Besides, four specific cases are considered in this research,
such as [15 , 44, 45]:
- Case 1: No harmonic source in the power network system
- Case 2: Harmonic source at downstream of the PCC
- Case 3: Harmonic sources at upstream and downstream of the PCC
- Case 4: Harmonic source at upstream of the PCC
(a) (b)
Figure 1. (a) Upstream-downstream for case 1, (b) IEEE 4-bus test feeders for case 2, 3 and 4
3. RESULTS AND ANALYSIS
In this section, it is explained the results of the research and at the same time is given
the comprehensive discussion. Results can be presented in figures and tables.
4. TELKOMNIKA Telecommun Comput El Control
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3.1. Case 1: No harmonic source in the power network system
The linear load, which is resistive loads, are located upstream and downstream of the PCC. As can be
seen in Figures 2 (a) and (b) show the measured voltage and current signals in the time domain. The peak
voltage is 326.5 V. In contrast, the peak current is 66.5 A, respectively. Besides, Figure 2 (c) shows the THD(t)
and TnHD(t) of voltage and both parameters are zero percent. Meanwhile, Figure 2 (d) presents the THD(t)
and TnHD(t) of current and both parameters are zero percent too. It shows that the voltage and current signal
have neither harmonic nor interharmonic components. Figure 2 (e) shows the ZTFR of the PCC, while
Figure 2 (f) presents the ZS. The most striking result from ZS, it is shown that the Z1 at 50 Hz is of 4.8 ohm and
no harmonic impedances exist. Thus, for case 1, the significant relationship between Z1 and Zh at the condition
of no harmonic source in the power system network, where for harmonic component, h is any positive integer
whereas, for interharmonic, h is any positive non-integer. can be written as:
𝑍1 ≠ 0 𝑜ℎ𝑚 (7)
𝑍ℎ ≠ 0 𝑜ℎ𝑚 (8)
(a) (b)
(c) (d)
(e) (f)
Figure 2. Case 1; (a) voltage signal in time domain, (b) current signal in time domain,
(c) THD(t) and TnHD(t) of voltage, (d) THD(t) and TnHD(t) of current,
(e) TFR of impedance (ZTFR), (f) spectral impedance component
3.2. Case 2: Harmonic source at downstream of the PCC
For case 2, the harmonic source is located downstream of the PCC. As can be seen in Figure 3 (a) and
Figure 3 (b) show the measured voltage and current signals in the time domain. The peak voltage is 326.5 V.
In contrast, the peak current is 66.5 A, respectively. In addition, Figure 3 (c) shows the THD(t) and TnHD(t)
mean of voltage are 1.51% and 6.05%, respectively. In the meantime, Figure 3 (d) presents the THD(t) and
TnHD(t) mean of current, which are 1.67% and 6.68%, respectively. The values of THD(t) and TnHD(t) show
5. ISSN: 1693-6930
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2712
that the voltage and current signals do have harmonic and interharmonic components. Figure 3 (e) shows
the ZTFR of the PCC and the ZS is obtained by extracting the parameters from the ZTFR. Meanwhile, Figure 3 (f)
presents the ZS that consists of the Z1. In contrast the harmonic impedance consists of Z275, Z375, Z600, Z700, Z825
and Z900, respectively. It is crucial to observe the relationship of ZS components due to identify the harmonic
source location in the power system network. Interestingly, as shown in Table 1, the Z1 value at 50 Hz, is
always higher than any Zh. Thus, for case 2, the significant relationship between Z1 and Zh at the condition of
the harmonic source located at downstream of the PCC can be concluded and written as:
𝑍1 ≠ 0 𝑜ℎ𝑚 (9)
𝑍ℎ < 𝑍1 (10)
where for harmonic component, h is any positive integer whereas, for interharmonic, h is any positive
non-integer.
(a) (b)
(c) (d)
(e) (f)
Figure 3. Case 2; (a) voltage signal in time domain, (b) current signal in time domain,
(c) THD(t) and TnHD(t) of voltage, (d) THD(t) and TnHD(t) of current,
(e) TFR of impedance (ZTFR), (f) spectral impedance component
3.3. Case 3: Harmonic sources at upstream and downstream of the PCC
For case 3, the harmonic source is located upstream and downstream of the PCC. As can be seen in
Figures 4 (a) and (b) show the measured voltage and current signals in the time domain. The peak voltage is
6. TELKOMNIKA Telecommun Comput El Control
Accurate harmonic source identification using S-transform (Mohd Hatta Jopri)
2713
324.7 V, while the peak current is 44.6 A, respectively. Besides, Figure 4 (c) shows the THD(t) and TnHD(t)
mean of voltage are 1.47% and 6.04%, respectively. In the meantime, Figure 4 (d) presents the THD(t) and
TnHD(t) mean of current, which are 1.91% and 45.18%, respectively. The values of THD(t) and TnHD(t) show
that the voltage and current signals do have harmonic and interharmonic components. Figure 4 (e) shows
the ZTFR of the PCC, while Figure 4 (f) presents the ZS that been extracted from the ZTFR. Furthermore,
Figure 4 (f) shows that the Z1 is 5.36 ohm; in contrast the harmonic impedance consists of Z275, Z375, Z400, Z600,
Z700 and Z900, respectively. The characteristic of the spectral impedance, ZS are summarized in Table 2. What is
surprising is that the value of Z1 is always smaller than any harmonic impedances, Zh. It is apparent from
the result that the ZS components can be characterized due to identify the location of the harmonic source.
As a result, for case 3, the significant relationship between Z1 and Zh at the condition of the harmonic source
located downstream of the PCC can be written as:
𝑍1 ≠ 0 𝑜ℎ𝑚 (11)
𝑍ℎ > 𝑍1 (12)
where for harmonic component, h is any positive integer whereas, for interharmonic, h is any positive
non-integer.
(a) (b)
(c) (d)
(e) (f)
Figure 4 Case 3; (a) voltage signal in time domain, (b) current signal in time domain,
(c) THD(t) and TnHD(t) of voltage, (d) THD(t) and TnHD(t) of current,
(e) TFR of impedance (ZTFR), (f) spectral impedance component
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Table 1. Magnitudes of the spectral impedance for
case 2 using S-transform technique
Spectral Impedance Ohm
Z1 5.36
Z275 3.81
Z375 3.68
Z600 4.19
Z700 4.34
Z825 3.94
Z900 3.68
Table 2. Magnitudes of the spectral impedance for
case 3 using S-transform technique
Spectral Impedance Ohm
Z1 6.5
Z275 12.8
Z375 11.8
Z400 12.3
Z600 12.2
Z700 12.5
Z900 12.9
3.4. Case 4: Harmonic source at upstream of the PCC
In case 4, the harmonic source is located upstream of the PCC. The voltage and current signals in
the time domain are measured at the PCC are shown in Figures 5 (a) and (b). The peak voltage is 324.3 V,
whereas the peak current is 30.65 A and the fundamental frequency is 50 Hz. These signals are used as
the inputs for analyzing harmonic sources using the S-transform technique. It can be seen from the waveforms
that the voltage and current waveforms are distorted because of the harmonic source presents in the network
system. Furthermore, Figure 5 (c) shows the THD(t) and TnHD(t) mean of voltage, which are 1.47%
and 6.04%, respectively. Moreover, Figure 5 (d) shows the THD(t) and TnHD(t) mean of current are 1.5%
and 6.05%, respectively. The values of THD(t) and TnHD(t) show that the voltage and current signals do have
harmonic and interharmonic components. The ZS components are extracted from the ZTFR shown in
Figure 5 (e). As shown in Figure 5 (f), the spectral impedance, ZS, consists of fundamental impedance, Z1 at 50
Hz, whereas the harmonic impedances such as Z275, Z300, Z375, Z400, Z600, Z700, Z900, respectively.
(a) (b)
(c) (d)
(e) (f)
Figure 5. Case 4, (a) Voltage signal in time domain, (b) Current signal in time domain,
(c) THD(t) and TnHD(t) of voltage, (d) THD(t) and TnHD(t) of current,
(e) TFR of impedance (ZTFR), (f) Spectral impedance component
8. TELKOMNIKA Telecommun Comput El Control
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The ZS components relationship are the critical driving factor of harmonic source identification and
the values of the components are summarized in Table 3. It can be seen that the Z1 is always the same value as
all harmonic impedances, Zh. Based on the results, it can be concluded that the ZS components can be used to
identify the location of harmonic sources. Hence, for case 4, the significant relationship between Z1 and Zh at
the condition of the harmonic source located at downstream of the PCC can be written as:
𝑍1 ≠ 0 𝑜ℎ𝑚 (13)
𝑍ℎ = 𝑍1 (14)
where for harmonic component, h is any positive integer whereas, for interharmonic, h is any positive
non-integer.
Table 3. Magnitudes of the spectral impedance for case 4 using S-transform technique
Spectral Impedance Ohm
Z1 10.6
Z275 10.6
Z300 10.6
Z375 10.6
Z400 10.6
Z600 10.6
Z700 10.6
Z900 10.6
3.5. Performance of the proposed method
This research provides an exciting opportunity to advance the understanding of harmonic source
identification using the S-transform technique. The main contribution of this analysis is the significant
relationship of the spectral impedance components, ZS such as fundamental impedance, Z1 and harmonic
impedance, Zh in identifying the location of the harmonic source in the network system. The spectral impedance
characteristics are used to identify the location of harmonic sources and the performance of this proposed
method are summarizes in Table 4.
Table 4. Performance of harmonic source identification using spectral impedance components characteristics
Case Upstream side Downstream side Spectral impedance, ZS characteristic % Correct identification
1 N N Z1 ≠ 0 ohm
Zh = 0 ohm
100
2 N H Z1≠ 0 ohm
Z1 > Zh
100
3 H H Z1 ≠ 0 ohm
Zh > Z1
100
4 N H Z1 ≠ 0 ohm
Zh = Z1
100
4. CONCLUSION
The main concern of this research is to identify the location of harmonic source that connected to
the distribution system utilizing the S-transform technique. The main contribution of this research is
the significant relationship of ZS components that obtained from the S-transform analysis in identifying
the location of harmonic sources. Based on Table 4, the correctness of the proposed method is 100% for each
case and the significant relationship of ZS for identification of harmonic source location are summarized
as follow:
- If Z1 ≠ 0 and Zh = 0, there is no source in the network system.
- If Z1≠ 0 and Z1 > Zh, there is a harmonic source located at downstream of the PCC.
- If Z1≠ 0 and Zh > Z1, there are a harmonic sources located at upstream and downstream of the PCC.
- If Z1 ≠ 0 and Z1 = Zh, there is a harmonic source located at upstream of the PCC.
Consequently, considering the results, this method can be used accurately in distinguishing the location of
the harmonic source.
9. ISSN: 1693-6930
TELKOMNIKA Telecommun Comput El Control, Vol. 18, No. 5, October 2020: 2708 - 2717
2716
ACKNOWLEDGEMENTS
This research is supported by the Advanced Digital Signal Processing Laboratory (ADSP Lab).
Special thanks also to the Faculty of Electrical and Electronic Engineering Technology of Universiti Teknikal
Malaysia Melaka (UTeM), Center for Robotics and Industrial Automation (CeRIA) of UTeM and Ministry of
Higher Education Malaysia (MOHE). Their support is gratefully acknowledged.
REFERENCES
[1] D. D. Ferreira et al., “Method based on independent component analysis for harmonic extraction from power system
signals,” Electr. Power Syst. Res., vol. 119, pp. 19-24, February 2015.
[2] M. Mishra, “Power quality disturbance detection and classification using signal processing and soft computing
techniques: A comprehensive review,” International Transactions on Electrical Energy Systems, vol. 29, no. 2,
March 2019.
[3] M. Farhoodnea, et al., “An improved method for determining contribution of utility and customer harmonic
distortions in a power distribution system,” Int. J. Electr. Eng. Informatics, vol. 2, no. 3, pp. 204-215, 2010.
[4] M. Farhoodnea, A. Mohamed, and H. Shareef, “A single point measurement method for evaluating harmonic
contributions of utility and customer in power distribution systems,” Journal of Applied Sciences, vol. 11, no. 2.
pp. 257-265, February 2011.
[5] A. R. Abdullah, et al., “Localization of multiple harmonic sources for inverter loads utilizing periodogram,”
J. Teknol., vol. 8, no. 2, pp. 87-91, January 2016.
[6] W. Xu, “Power direction method cannot be used for harmonic source detection,” 2000 Power Engineering Society
Summer Meeting (Cat. No.00CH37134), vol. 2, pp. 873-876, July 2000.
[7] F. Xu, et al., “Study on constraints for harmonic source determination using active power direction,” IEEE Trans.
Power Deliv., vol. 33, no. 6, pp. 2683-2692, Dec. 2018.
[8] Y. Liu, et al., “Harmonic source location at the point of common coupling based on the nonlinearity index of load,”
2009 Asia-Pacific Power and Energy Engineering Conference, 2009, pp. 1-5, March 2009.
[9] A. R. Abdullah, G. Z. Peng and S. A. Ghani, “A new vector draft method for harmonic source detection at point of
common coupling,” Proc. 2014 IEEE 8th Int. Power Eng. Optim. Conf. PEOCO 2014, pp. 110-114, March 2014.
[10] F. Safargholi, K. Malekian, and W. Schufft, “On the dominant harmonic source identification-Part II: Application
and interpretation of methods,” IEEE Transaction on Power Delivery, vol. 33, no. 3, pp. 1278-1287, Jun. 2018.
[11] F. Safargholi, K. Malekian, and W. Schufft, “On the dominant harmonic source identification - Part I: Review of
Methods,” IEEE Trans. Power Deliv., vol. 33, no. 3, pp. 1268-1277, Jun. 2018.
[12] A. R. Abdullah, et al., “Localization of multiple harmonic sources for inverter loads utilizing periodogram,”
J. Telecommun. Electron. Comput. Eng., vol. 8, no. 2, 2016.
[13] A. Abdullah, M. Manap, et al., “An improved spectrogram to identify multiple harmonic sources in distribution
system with inverter loads,” Proceedings of the International MultiConference of Engineers and Computer
Scientists., vol. II, pp. 0-5, March 2017.
[14] N. Hamzah, et al., “Identification of harmonic source at the point of common coupling based on voltage indices,”
J. Teknol., vol. 43, no. 1, pp. 11-32, Dec. 2005.
[15] A. Abdullah, and M. Manap, “An improved spectrogram to identify multiple harmonic sources in distribution system
with inverter loads,” Proceedings of the International MultiConference of Engineers and Computer Scientists.,
vol. 7, no. 4, pp. 11591, 2017.
[16] A. Banshwar and A. K. Chandel, “Identification of harmonic sources using fuzzy logic,” 2010 Jt. Int. Conf. Power
Electron. Drives Energy Syst. 2010 Power India, pp. 1–7, December 2010.
[17] C. Jaipradidtham, “A control of real voltage and harmonic analysis with adaptive static var of electric arc furnace for
power quality improvement by Grey Markov method,” 2016 IEEE 6th Int. Conf. Power Syst. ICPS 2016, no. 1,
March 2016.
[18] T. Zang, et al., “Harmonic source localization approach based on fast kernel entropy optimization ICA and minimum
conditional entropy,” Entropy, vol. 18, no. 6, pp. 214, June 2016.
[19] T. Pfajfar, B. Blažič, and I. Papič, “Harmonic contributions evaluation with the harmonic current vector method,”
IEEE Transactions on Power Delivery, vol. 23, no. 1, pp. 425-433, January 2008.
[20] A. R. Abdullah, et al., “An identification of multiple harmonic sources in a distribution system by using
spectrogram,” Bulletin of Electrical. Engineering and Informatics, vol. 7, no. 2, pp. 244-256, June 2018.
[21] P. Supriya and T. N. Padmanabhan Nambiar, “Review of harmonic source identification techniques,” International.
Review. Electrical. Engineering., vol. 7, no. 3, pp. 4525-4531, June 2012.
[22] G. D’Antona, et al., “Harmonic source estimation in distribution systems,” Appl. Meas. Power Syst. (AMPS), 2010
IEEE Int. Work., vol. 60, no. 10, pp. 1-5, September 2010.
[23] A. R. Abdullah, et al., “A fast localization of multiple harmonic sources for rectifier loads by utilizing periodogram,”
Telkomnika (Telecommunication Computer. Electronics. and Control., vol. 15, no. 1, March 2017.
[24] A. Rahim Abdullah, et al., “Performance evaluation of real power quality disturbances analysis using S-transform,”
Appl. Mech. Mater., vol. 752–753, pp. 1343-1348, April 2015.
[25] A. R. Abdullah, et al., “Short-circuit switches fault analysis of voltage source inverter using spectrogram,” Electr.
Mach. Syst. (ICEMS), 2013 Int. Conf., pp. 1808-1813, October 2013.
10. TELKOMNIKA Telecommun Comput El Control
Accurate harmonic source identification using S-transform (Mohd Hatta Jopri)
2717
[26] N. A. Abidullah, et al., “Real-time power quality signals monitoring system,” Proceeding - 2013 IEEE Student
Conference on Research and Development, SCOReD 2013, January 2015.
[27] A. Abdullah, et al., “A utilisation of improved gabor transform for harmonic signals detection and classification
analysis,” International. Journal of Electrical and Computer Engineering, vol. 7, no. 1, pp. 21-28, February 2017.
[28] A. R. Abdullah, et al., “An improved of multiple harmonic sources identification in distribution system with inverter
loads by using spectrogram,” Bull. Electr. Eng. Informatics, vol. 7, no. 2, pp. 244-256, December 2018.
[29] A. R. Abdullah, et al., “An accurate classification method of harmonic signals in power distribution system
by utilising S-transform,” TELKOMNIKA Telecommunication, Computing, Electronics and Control, vol. 15, no. 1,
pp. 12-20, March 2017.
[30] A. R. Abdullah, et al., “Power quality signals classification system using time-frequency distribution,” Appl. Mech.
Mater., vol. 494-495, pp. 1889-1894, 2014.
[31] A. R. Abdullah, et al., “Performance verification of power quality signals classification system,” Applied. Mechanics
and. Materials., vol. 753, pp. 1158-1163, April 2015.
[32] A. R. Abdullah, et al., “An improved detection and classification technique of harmonic signals in power distribution
by utilizing spectrogram,” International Journal Electrical and Computer Engineering, vol. 7, no. 1, pp. 12-20, 2017.
[33] A. G. Miamee, “Nonstationary stochastic processes and their applications,” Workshop on Nonstationary Stochastic
Processes and Their Application, pp. 1-298, August 1991.
[34] N. H. T. Ahmad, A. R. Abdullah and N. A. Abidullah, “Analysis of power quality disturbances using spectrogram
and S-transform,” International Review of Electrical Engineering, vol. 9, no. 3, pp. 611-619, June 2014.
[35] A. R. Abdullah, et al., “A critical review of time-frequency distribution analysis for detection and classification of
harmonic signal in power distribution system,” International Journal Electrical and. Computer Engineering, vol. 8,
no. 6, pp. 4603-4618, December 2018.
[36] N. A. Abidullah, et al., “Real-time power quality signals monitoring system,” Proceeding - 2013 IEEE Student Conf.
Res. Dev. SCOReD 2013, pp. 433-438, December 2013.
[37] N. H. T. Huda, A. R. Abdullah, et al., “Power quality signals detection using S-transform,” Proc. 2013 IEEE 7th Int.
Power Eng. Optim. Conf. PEOCO 2013, pp. 552-557, June 2013.
[38] C.-I. Chen and Y. Chen, “A neural-network-based data-driven nonlinear model on time- and frequency-domain
voltage-current characterization for power-quality study,” IEEE Transaction on Power Delivery, vol. 30, no. 3,
pp. 1577-1584, Jun. 2015.
[39] J. Wu, et al., “Identification of multiple harmonic sources in cyber-physical energy system using supervised
independent component analysis,” 2014 IEEE International Instrumentation and Measurement Technology
Conference , pp. 496-501, 2014.
[40] M. Manap, et al., “Comparison of open and short-circuit switches faults voltage source inverter (VSI) analysis using
time-frequency distributions,” Applied Mechanics and Materials., vol. 752–753, pp. 1164-1169, April 2015.
[41] M. L. Baughman and R. C. Dugan, “IEEE 4 Node Test Feeder,” Inst. Electr. Electron. Eng. Inc, pp. 1-9, 2009.
[42] A. K. Bharati and V. Ajjarapu, “Investigation of relevant distribution system representation with DG for voltage
stability margin assessment,” IEEE Transaction on Power System, vol, 99, pp. 1-1, Oct. 2019.
[43] M. J. E. Alam, K. M. Muttaqi, and D. Sutanto, “A three-phase power flow approach for integrated 3-wire MV and 4-wire
multigrounded LV networks with rooftop solar PV,” IEEE Trans. Power Syst., vol. 28, no. 2, pp. 1728-1737, 2013.
[44] M. Narimani, S. H. Hosseinian, and B. Vahidi, “A method for harmonic power tracing by using upstream and
downstream distribution matrices,” Electr. Power Components Syst., vol. 47, no. 13, pp. 1169-1179, Aug. 2019.
[45] P. Sinha, S. K. Goswami, and S. Debnath, “Harmonic source identification in distribution system using non-active
power quantities,” Int. J. Power Energy Convers., vol. 8, no. 1, pp. 90-111, January 2017.