hashim hizam | UPM - Universiti Putra Malaysia (original) (raw)
Papers by hashim hizam
High frequency signals generated due to faults contain information which could be utilised to loc... more High frequency signals generated due to faults contain information which could be utilised to locate the faults. Based on the principle of reverberation of waves on power network, the high frequency signature of the current signals are related to known reflection points exist in the network. From these the fault section and the probable location of the fault can be identified. The probable location is then used within a power system simulator that models the network. The simulated current waveforms at the probable locations are then cross-correlated against the signals captured. If the identified location is correct, the high frequency signature in the simulated waveform will be similar to that observed in the measured waveform and the cross-correlation value will have a high positive value. If the signatures differ, the cross-correlation value will be small. Simulation studies using PSCAD/EMTDC and analysis using cross-correlation indicate that locating faults on a radial distribution feeder is a possibility using a single ended travelling wave measurement method.
Journal of Applied Sciences, 2007
This study describes a technique to estimate the location of faults on a radial distribution netw... more This study describes a technique to estimate the location of faults on a radial distribution network based on the principles of travelling waves. The occurrence of faults on power systems will result in the high frequency voltage and current signals to propagate along the power systems. These signals contain a lot of information and can be used for fault location.
Among breakdowns reported in Tenaga Nasional Berhad (TNB) Malaysia is about 60% of total breakdow... more Among breakdowns reported in Tenaga Nasional Berhad (TNB) Malaysia is about 60% of total breakdown is due to underground network failures. It was known that cable joint is the weakest part in the underground cable system and ferrule is one part of cable joint. The main reason of ferrule failure is due to excessive heat generated at the connection between conductor and ferrule. There are many ferrules available in the market. This study will focus on two types of ferrule and the experiment was setup to evaluate the thermal performance.
Blockset toolbox available in MATLAB program.
Journal of Crystal Growth, 2005
This paper presents a design of pole placement controller for D-STATCOM for unbalanced faults mit... more This paper presents a design of pole placement controller for D-STATCOM for unbalanced faults mitigation. In the pole placement method the poles are shifted to the new poles location at the real-imaginary axes for better response. This type of controller is able to control the amount of injected current from the D-STATCOM to compensate the unbalanced faults by referring to the current which are the inputs to the controller. The controller efficiency was tested under unbalanced faults which are single line to ground (SLG) fault and double phase to ground (DPG) fault. The controller and the D-STATCOM were designed using SIMULINK and power system blockset toolbox that is available in MATLAB. The controller block was designed based on the signal flow diagram
Active power filter appears to be a viable solution for power quality conditioning. With the emer... more Active power filter appears to be a viable solution for power quality conditioning. With the emergence of fast computing devices, control strategies for active filters are continually changing aiming at near perfect compensation. This paper presents a review of the state-of-the-art control techniques in active filters and reactive power compensation. Considerable attention is paid to the reference voltage/current estimation and control strategies. Several techniques are discussed and compared in terms of performance and implementation.
One of the most current and widely discussed factors that could lead to the ultimate end of man&a... more One of the most current and widely discussed factors that could lead to the ultimate end of man's existence and the world at large is global warming. Global warming, described as the greatest environmental challenge in the 21st century, is the increase in the average global air temperature near the surface of the Earth, caused by the gases that trap
Abstract Undesirable radiated electromagnetic fields because of switched current are causing the ... more Abstract Undesirable radiated electromagnetic fields because of switched current are causing the Electromagnetic Interference (EMI). This disturbance affects electrical circuit due to electromagnetic radiation emitted from EMI source. The effect of EMI can be diminished by reducing the generated EMI in the source. In the low-power circuit by using a grounded shield the magnitude of emitted EMI may be reduced to ignorable value, but in high-power circuits due to the cooling limitations, using the ground shield is not feasible. In this paper, ...
Electric Power Components and Systems, 2011
This article presents a classification methodology based on probabilistic neural networks. To aut... more This article presents a classification methodology based on probabilistic neural networks. To automatically select the training data and obtain the performance evaluation results, the “K-fold” cross-validation method is used. Then, the probabilistic neural network is compared with the feed-forward neural network and the radial basis function network. The goal is to propose a classifier that is capable of recognizing 11 classes of three-phase distribution system faults to solve the complex fault (three-phase short-circuit) classification problem for reducing the multiple-estimation problem to estimate the fault location in radial distribution systems. The data for the fault classifier is produced by DigSilent Power Factory, Integrated Power System Analysis Software on an IEEE 13-node test feeder. A selection of features or descriptors obtained from voltages and currents measured in the substation are analyzed and used as input of the probabilistic neural network classifier. It is shown that the probabilistic neural network approach can provide a fast and precise operation for various faults. The simulation results also show that the proposed model can successfully be used as an effective tool for solving complicated classification problems.
The growth of large interconnected electricity networks requires a high degree of security for no... more The growth of large interconnected electricity networks requires a high degree of security for normal operation. This paper attempts to overview several available techniques for assessing the Transient Security Assessment (TSA) of a power system. Different algorithms are explained in details (Static and Dynamic Security Assessment) with the uses of Artificial Intelligent (AI) method. Transient effects can be roughly described as undesired voltage/ current that may result a contingencies in the power system. However, it is only considered lightning and switching as the main causes of TSA. In this proposed method, Artificial Neural Network (ANN) and Fuzzy techniques are able to use in term of classification, prediction and to determine the system security status. Time domain analysis is performed for each credible contingency using signal processing method; than an AI model is proposed for the TSA analysis. The novelty of the proposed approach is that the fast ability to detect and classify any disturbance (lightning (or) switching) in the electric power system using AI techniques.
Journal of Applied Sciences, 2008
Journal of Applied Sciences, 2010
... and flux linkages of quadrate and direct axes components are written as (Rahim and Baber-Abba... more ... and flux linkages of quadrate and direct axes components are written as (Rahim and Baber-Abbas, 2007): VVF : —inir ldsm ]]) L eli D (14) Lip 1 ... other types that are known unsymmetrical voltage sags, one type has the serious effect on the performance of the system (Guasch et al ...
Voltage collapse is an event that causes major concern to the power system utility nowadays. The ... more Voltage collapse is an event that causes major concern to the power system utility nowadays. The effect can be catastrophic to the power system where it can cause total collapse to the operation of the system. The study of the voltage collapse phenomenon can provide a way to prevent this event from happening. There have been many methods developed to
One of the major constraints faced in the teaching of power system analysis courses has been non-... more One of the major constraints faced in the teaching of power system analysis courses has been non-availability of practical power system for demonstration. This paper focuses on a new and efficient method to the teaching of power system analysis courses to the upper-division undergraduate students. The intent is to present MATPOWER to students as a good instructional tool to complement
Calculation of the load peak voltage, potential energy and power consumption of a Marx impulse ge... more Calculation of the load peak voltage, potential energy and power consumption of a Marx impulse generator, as a function of time, are presented. The equations are generalized and can be used to the design of any type of n-stage Marx impulse generator. The results were validated for a thyristor controlled Marx impulse generator with a maximum number of stages of 10 and 3 kV input DC voltage, which used 1 MΩ resistors and 33 nF capacitors in its topology.
Nowadays considering more accuracy and speed to compute Available Transfer Capabilities (ATC) are... more Nowadays considering more accuracy and speed to compute Available Transfer Capabilities (ATC) are important for electricity markets. Most studies involved load flow based and contingencies that often can be performed in reasonable time with the use of linear methods. Since the limitations of linear ATC calculations is the error produced by neglecting the nonlinear nature of real power flows. This paper presents Krylov Subspace methods that can reduce this error. By applying these methods for calculating ATC, the speed and the accuracy of them are calculated and compared to find the best one. All computations are tested on IEEE-30 bus system in MATLAB 7.1.
This paper presents the application of linear feedback controller on distribution static synchron... more This paper presents the application of linear feedback controller on distribution static synchronous compensator (D-STATCOM) for mitigating double phase to ground (DPG) fault at the distribution system. The pole placement technique is applied by shifting the existing poles to the new poles locations for fast response compare to the conventional controller. This type of inverter control is very useful in D-STATCOM application which controls the inverter to inject the unbalanced current or voltage or both for mitigating the fault condition that occurs at the distribution system. The controller will give respond to the lines that are affected by the fault and restore the system to its normal conditions. The simulation and design of the controller is done using MATLAB software with Power Blockset Toolbox and SIMULINK
The effectiveness of a grounding system is highly dependent on several parameters such as its siz... more The effectiveness of a grounding system is highly dependent on several parameters such as its size, i.e. the length of the ground conductor, the electrical characteristics of the ground conductor and its surrounding soil. A single long horizontal ground conductor being a basic configuration of a grounding system could act as a path for the transient currents to be easily
Energy & Environment, 2010
Delivery of electrical power to the end users by the wires systems (grids) has been in practice f... more Delivery of electrical power to the end users by the wires systems (grids) has been in practice for more than seven decades. However, recent global renewed interest in distributed generation is due to the constraints or shortcomings of this traditional method. ...
In this paper, the application of an Artificial Neural Network (ANN) for remedial action of a pow... more In this paper, the application of an Artificial Neural Network (ANN) for remedial action of a power system is presented. The aims of this study are to find the significant control action that alleviates a bus voltage violation of a power system and to demonstrate the ability of a neural network in terms of evaluating the generation re-dispatch and load shedding amounts. The remedial action is based on a steady-state security assessment of the power system. The proposed algorithm has been successfully tested on a 9-bus test system. The results are compared with other conventional methods and it reveals that an ANN can provide the required amount of generation re-dispatch and load shedding accurately and instantaneously compared to other methods. On average, remedial actions were shown to have a positive effect for reducing the number of bus voltage violations and improving system security.
High frequency signals generated due to faults contain information which could be utilised to loc... more High frequency signals generated due to faults contain information which could be utilised to locate the faults. Based on the principle of reverberation of waves on power network, the high frequency signature of the current signals are related to known reflection points exist in the network. From these the fault section and the probable location of the fault can be identified. The probable location is then used within a power system simulator that models the network. The simulated current waveforms at the probable locations are then cross-correlated against the signals captured. If the identified location is correct, the high frequency signature in the simulated waveform will be similar to that observed in the measured waveform and the cross-correlation value will have a high positive value. If the signatures differ, the cross-correlation value will be small. Simulation studies using PSCAD/EMTDC and analysis using cross-correlation indicate that locating faults on a radial distribution feeder is a possibility using a single ended travelling wave measurement method.
Journal of Applied Sciences, 2007
This study describes a technique to estimate the location of faults on a radial distribution netw... more This study describes a technique to estimate the location of faults on a radial distribution network based on the principles of travelling waves. The occurrence of faults on power systems will result in the high frequency voltage and current signals to propagate along the power systems. These signals contain a lot of information and can be used for fault location.
Among breakdowns reported in Tenaga Nasional Berhad (TNB) Malaysia is about 60% of total breakdow... more Among breakdowns reported in Tenaga Nasional Berhad (TNB) Malaysia is about 60% of total breakdown is due to underground network failures. It was known that cable joint is the weakest part in the underground cable system and ferrule is one part of cable joint. The main reason of ferrule failure is due to excessive heat generated at the connection between conductor and ferrule. There are many ferrules available in the market. This study will focus on two types of ferrule and the experiment was setup to evaluate the thermal performance.
Blockset toolbox available in MATLAB program.
Journal of Crystal Growth, 2005
This paper presents a design of pole placement controller for D-STATCOM for unbalanced faults mit... more This paper presents a design of pole placement controller for D-STATCOM for unbalanced faults mitigation. In the pole placement method the poles are shifted to the new poles location at the real-imaginary axes for better response. This type of controller is able to control the amount of injected current from the D-STATCOM to compensate the unbalanced faults by referring to the current which are the inputs to the controller. The controller efficiency was tested under unbalanced faults which are single line to ground (SLG) fault and double phase to ground (DPG) fault. The controller and the D-STATCOM were designed using SIMULINK and power system blockset toolbox that is available in MATLAB. The controller block was designed based on the signal flow diagram
Active power filter appears to be a viable solution for power quality conditioning. With the emer... more Active power filter appears to be a viable solution for power quality conditioning. With the emergence of fast computing devices, control strategies for active filters are continually changing aiming at near perfect compensation. This paper presents a review of the state-of-the-art control techniques in active filters and reactive power compensation. Considerable attention is paid to the reference voltage/current estimation and control strategies. Several techniques are discussed and compared in terms of performance and implementation.
One of the most current and widely discussed factors that could lead to the ultimate end of man&a... more One of the most current and widely discussed factors that could lead to the ultimate end of man's existence and the world at large is global warming. Global warming, described as the greatest environmental challenge in the 21st century, is the increase in the average global air temperature near the surface of the Earth, caused by the gases that trap
Abstract Undesirable radiated electromagnetic fields because of switched current are causing the ... more Abstract Undesirable radiated electromagnetic fields because of switched current are causing the Electromagnetic Interference (EMI). This disturbance affects electrical circuit due to electromagnetic radiation emitted from EMI source. The effect of EMI can be diminished by reducing the generated EMI in the source. In the low-power circuit by using a grounded shield the magnitude of emitted EMI may be reduced to ignorable value, but in high-power circuits due to the cooling limitations, using the ground shield is not feasible. In this paper, ...
Electric Power Components and Systems, 2011
This article presents a classification methodology based on probabilistic neural networks. To aut... more This article presents a classification methodology based on probabilistic neural networks. To automatically select the training data and obtain the performance evaluation results, the “K-fold” cross-validation method is used. Then, the probabilistic neural network is compared with the feed-forward neural network and the radial basis function network. The goal is to propose a classifier that is capable of recognizing 11 classes of three-phase distribution system faults to solve the complex fault (three-phase short-circuit) classification problem for reducing the multiple-estimation problem to estimate the fault location in radial distribution systems. The data for the fault classifier is produced by DigSilent Power Factory, Integrated Power System Analysis Software on an IEEE 13-node test feeder. A selection of features or descriptors obtained from voltages and currents measured in the substation are analyzed and used as input of the probabilistic neural network classifier. It is shown that the probabilistic neural network approach can provide a fast and precise operation for various faults. The simulation results also show that the proposed model can successfully be used as an effective tool for solving complicated classification problems.
The growth of large interconnected electricity networks requires a high degree of security for no... more The growth of large interconnected electricity networks requires a high degree of security for normal operation. This paper attempts to overview several available techniques for assessing the Transient Security Assessment (TSA) of a power system. Different algorithms are explained in details (Static and Dynamic Security Assessment) with the uses of Artificial Intelligent (AI) method. Transient effects can be roughly described as undesired voltage/ current that may result a contingencies in the power system. However, it is only considered lightning and switching as the main causes of TSA. In this proposed method, Artificial Neural Network (ANN) and Fuzzy techniques are able to use in term of classification, prediction and to determine the system security status. Time domain analysis is performed for each credible contingency using signal processing method; than an AI model is proposed for the TSA analysis. The novelty of the proposed approach is that the fast ability to detect and classify any disturbance (lightning (or) switching) in the electric power system using AI techniques.
Journal of Applied Sciences, 2008
Journal of Applied Sciences, 2010
... and flux linkages of quadrate and direct axes components are written as (Rahim and Baber-Abba... more ... and flux linkages of quadrate and direct axes components are written as (Rahim and Baber-Abbas, 2007): VVF : —inir ldsm ]]) L eli D (14) Lip 1 ... other types that are known unsymmetrical voltage sags, one type has the serious effect on the performance of the system (Guasch et al ...
Voltage collapse is an event that causes major concern to the power system utility nowadays. The ... more Voltage collapse is an event that causes major concern to the power system utility nowadays. The effect can be catastrophic to the power system where it can cause total collapse to the operation of the system. The study of the voltage collapse phenomenon can provide a way to prevent this event from happening. There have been many methods developed to
One of the major constraints faced in the teaching of power system analysis courses has been non-... more One of the major constraints faced in the teaching of power system analysis courses has been non-availability of practical power system for demonstration. This paper focuses on a new and efficient method to the teaching of power system analysis courses to the upper-division undergraduate students. The intent is to present MATPOWER to students as a good instructional tool to complement
Calculation of the load peak voltage, potential energy and power consumption of a Marx impulse ge... more Calculation of the load peak voltage, potential energy and power consumption of a Marx impulse generator, as a function of time, are presented. The equations are generalized and can be used to the design of any type of n-stage Marx impulse generator. The results were validated for a thyristor controlled Marx impulse generator with a maximum number of stages of 10 and 3 kV input DC voltage, which used 1 MΩ resistors and 33 nF capacitors in its topology.
Nowadays considering more accuracy and speed to compute Available Transfer Capabilities (ATC) are... more Nowadays considering more accuracy and speed to compute Available Transfer Capabilities (ATC) are important for electricity markets. Most studies involved load flow based and contingencies that often can be performed in reasonable time with the use of linear methods. Since the limitations of linear ATC calculations is the error produced by neglecting the nonlinear nature of real power flows. This paper presents Krylov Subspace methods that can reduce this error. By applying these methods for calculating ATC, the speed and the accuracy of them are calculated and compared to find the best one. All computations are tested on IEEE-30 bus system in MATLAB 7.1.
This paper presents the application of linear feedback controller on distribution static synchron... more This paper presents the application of linear feedback controller on distribution static synchronous compensator (D-STATCOM) for mitigating double phase to ground (DPG) fault at the distribution system. The pole placement technique is applied by shifting the existing poles to the new poles locations for fast response compare to the conventional controller. This type of inverter control is very useful in D-STATCOM application which controls the inverter to inject the unbalanced current or voltage or both for mitigating the fault condition that occurs at the distribution system. The controller will give respond to the lines that are affected by the fault and restore the system to its normal conditions. The simulation and design of the controller is done using MATLAB software with Power Blockset Toolbox and SIMULINK
The effectiveness of a grounding system is highly dependent on several parameters such as its siz... more The effectiveness of a grounding system is highly dependent on several parameters such as its size, i.e. the length of the ground conductor, the electrical characteristics of the ground conductor and its surrounding soil. A single long horizontal ground conductor being a basic configuration of a grounding system could act as a path for the transient currents to be easily
Energy & Environment, 2010
Delivery of electrical power to the end users by the wires systems (grids) has been in practice f... more Delivery of electrical power to the end users by the wires systems (grids) has been in practice for more than seven decades. However, recent global renewed interest in distributed generation is due to the constraints or shortcomings of this traditional method. ...
In this paper, the application of an Artificial Neural Network (ANN) for remedial action of a pow... more In this paper, the application of an Artificial Neural Network (ANN) for remedial action of a power system is presented. The aims of this study are to find the significant control action that alleviates a bus voltage violation of a power system and to demonstrate the ability of a neural network in terms of evaluating the generation re-dispatch and load shedding amounts. The remedial action is based on a steady-state security assessment of the power system. The proposed algorithm has been successfully tested on a 9-bus test system. The results are compared with other conventional methods and it reveals that an ANN can provide the required amount of generation re-dispatch and load shedding accurately and instantaneously compared to other methods. On average, remedial actions were shown to have a positive effect for reducing the number of bus voltage violations and improving system security.