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Full-Text Articles in Physical Sciences and Mathematics
Grounding Locations Assessment Of Practical Power System, Nadheer Shalash, Ahmed M. Haidar, Abdul Sattar
Grounding Locations Assessment Of Practical Power System, Nadheer Shalash, Ahmed M. Haidar, Abdul Sattar
Faculty of Informatics - Papers (Archive)
Grounding Points (GPs) are installed in electrical power system to drive protective devices and accomplish the person- nel safety. The general grounding problem is to find the optimal locations of these points so that the security and reli- ability of power system can be improved. This paper presents a practical approach to find the optimal location of GPs based on the ratios of zero sequence reactance with positive sequence reactance (X0/X1), zero sequence resistance with positive sequence reactance (R0/X1) and Ground Fault Factor (GFF). The optimal values of these indicators were deter- mined by considering several scenarios of fault disturbances …
Power Line Enhancement For Data Monitoring Of Neural Electrical Activity In The Human Body, Ahmed M. Haidar, Sridhathan C, Abdulsalam Hazza, Ahmed Saleh
Power Line Enhancement For Data Monitoring Of Neural Electrical Activity In The Human Body, Ahmed M. Haidar, Sridhathan C, Abdulsalam Hazza, Ahmed Saleh
Faculty of Informatics - Papers (Archive)
Distance and real-time data monitoring are the necessary condition that makes any system in good working order. Recent advancements in micro-electronics and wireless technology enable the application of wireless sensors in both industry and wild environments. However, Long-distance wireless communication has several drawbacks like limited bandwidth, considerable costs and unstable connection quality. Therefore, Power Line Communication (PLC) using pre-established Power Lines (PL) becomes more attractive for high data transmission technology. This paper reviews the existing distance data monitoring systems and presents a case study for data transferring of temperature and heart beat measurement. The simulations were carried out on the …
Understanding The Conducting States Of Active And Passive Switches In An Inverter Circuit Used For Power System Applications, Danny Sutanto, B.P. Divakar, K.W.E. Cheng
Understanding The Conducting States Of Active And Passive Switches In An Inverter Circuit Used For Power System Applications, Danny Sutanto, B.P. Divakar, K.W.E. Cheng
Faculty of Informatics - Papers (Archive)
Bi-directional inverter circuits are commonly used in many applications in power systems, such as in FACTS devices, energy storage systems and active power filters. Many power engineering students however find it difficult to understand the conducting states of the active switches (transistors, IGBTs) and the passive switches (the antiparallel diodes connected across the active switches). It seems a mystery to them that power can flow from a lower voltage ac system to a higher voltage dc system to charge the energy storage system. This paper proposes a simple chart that intuitively explains how to determine the states (either conducting or …
Coordinated Utilisation Of Wind Farm Reactive Power Capability For System Loss Optimisation, Lasantha Meegahapola, S Durairaj, D Flynn, B Fox
Coordinated Utilisation Of Wind Farm Reactive Power Capability For System Loss Optimisation, Lasantha Meegahapola, S Durairaj, D Flynn, B Fox
Faculty of Informatics - Papers (Archive)
Most wind farms currently being installed are based upon doubly fed induction generator (DFIG) or direct-drive synchronous generator (DDSG) technology. Given that one of the impacts of introducing distributed generation is an alteration of steady-state power flows and voltages, both technologies are capable of providing local voltage support. Wind farms may, therefore, be included in optimal power flow (OPF) calculations to minimise fuel cost and/or network losses. The IEEE 30-bus system is considered as a case study, comparing fixed-speed induction generator (FSIG) requirements with DFIG capability. Results are presented for a range of DFIG capability modes, at varying system load …
An Intelligent Approach For Cost Minimization Of Power Generation, Ahmed M. A. Haidar, Ibrahim A. Ahmed, Norazila Jaalam
An Intelligent Approach For Cost Minimization Of Power Generation, Ahmed M. A. Haidar, Ibrahim A. Ahmed, Norazila Jaalam
Faculty of Informatics - Papers (Archive)
Cost reduction is one of the main targets in power industry due to economic load dispatch problem and allocating loads to plants for minimum cost. The principal objective in economic dispatch of thermal generators in a power system is to determine the economic loadings of the generators so that the load demand can be met and the loadings are within the feasible operating regions of the generators. This study presents an optimization approach for fuel cost and power loss minimization based on genetic algorithm and particle swarm optimization methods. To demonstrate the global optimization power of the presented techniques, these …
Monitoring Intelligent Distribution Power Systems: A Power Quality Plan, Neil R. Browne, Timothy J. Browne, Sean T. Elphick
Monitoring Intelligent Distribution Power Systems: A Power Quality Plan, Neil R. Browne, Timothy J. Browne, Sean T. Elphick
Faculty of Informatics - Papers (Archive)
Power system monitoring capabilities and requirements are evolving rapidly. The traditional monitoring framework in Australian distribution networks involves biannual readings of maximum demand at each distribution substation. As utilities respond to developments in metering and communications technology, automated collection and retrieval of quasi-real-time system data between substations and central repositories is now feasible. This gives network managers a significantly increased understanding of distribution network dynamic activity such as daily and seasonal load profiles. This leads to the increased ability of utilities to exploit metering data for power quality analysis purposes. This paper examines the scope for, and challenges associated with, …
On Optimising Route Discovery For Multi-Interface And Power-Aware Nodes In Heterogeneous Manets, Huda Alaamri, Mehran Abolhasan, Tadeusz A. Wysocki, Justin Lipman
On Optimising Route Discovery For Multi-Interface And Power-Aware Nodes In Heterogeneous Manets, Huda Alaamri, Mehran Abolhasan, Tadeusz A. Wysocki, Justin Lipman
Faculty of Informatics - Papers (Archive)
This paper presents a new routing discovery strategy for heterogeneous MANETs. Node heterogeneity is modeled in terms of: types and number of different interfaces, power, and transmission ranges. Our proposed route discovery algorithm is implemented on the top of On-demand Tree-based Routing Protocol (OTRP) and hence it is called OTRP Heterogeneity-Aware (OTRP HA). OTRP HA utilizes node heterogeneity and optimizes route discovery to reduce overheads and ensures connectivities between different types of nodes with different interfaces. Each node makes its own decision to participate in the route discovery process according to its location, local density, and available resources. Simulation results …
Optimisation Of Component Sizes For A Hybrid Remote Area Power Supply System, Saad M. Sayeef, Nishad Mendis, Kashem Muttaqi
Optimisation Of Component Sizes For A Hybrid Remote Area Power Supply System, Saad M. Sayeef, Nishad Mendis, Kashem Muttaqi
Faculty of Informatics - Papers (Archive)
In this paper, an optimisation model for determination of the optimal sizes of various system components, including wind, diesel and energy storage, has been developed to obtain a reliable and cost-effective wind-diesel hybrid remote area power supply (RAPS) system. A linear programming based cost minimisation algorithm has been formulated for determination of optimal sizes of various components in a RAPS system with consideration of continually varying wind and system load. The system constraints, including power balance for both under-generation and over-generation scenarios, have been considered in the optimisation formulation. Optimisation model to minimize the total cost of the system based …
Voltage Quality Behaviour Of A Wind Turbine Based Remote Area Power System, Nishad Mendis, Kashem Muttaqi, Sarath Perera
Voltage Quality Behaviour Of A Wind Turbine Based Remote Area Power System, Nishad Mendis, Kashem Muttaqi, Sarath Perera
Faculty of Informatics - Papers (Archive)
The power quality behaviour of a Remote Area Power System (RAPS) consisting of a Doubly Fed Induction Generator (DFIG), its main loads and a dummy load is presented in this paper. The dummy load is used to maintain the power balance of the system under changing wind and loading conditions. The performance of the remote area power system subject to various loading conditions has been evaluated in terms of the voltage quality, an aspect which has not received much attention in the past. The existing Distributed Generation (DG) power quality standards are taken as the basis to compare the voltage …
Routing Metric For Multi-Interface And Power-Aware Nodes In Heterogenous Manets, Huda Mubarak Al Amri, Mehran Abolhasan, Tadeusz A. Wysocki
Routing Metric For Multi-Interface And Power-Aware Nodes In Heterogenous Manets, Huda Mubarak Al Amri, Mehran Abolhasan, Tadeusz A. Wysocki
Faculty of Informatics - Papers (Archive)
This paper presents heterogeneity ratio (HR) as a new routing metric for heterogeneous MANETs. This metric is the ratio of number of powerful nodes to hop count that is used to select the best path to destination. Node heterogeneity is modeled in terms of: types and number of different interfaces, power, and transmission ranges. Our proposed routing metric is based on developing route discovery algorithm that is implemented on the top of on-demand tree-based routing protocol (OTRP)[2] to accommodate nodes heterogeneity. Simulation results show that using HR with OTRP heterogeneity aware outperforms other metrics like minimal hop count and maximal …
Vulnerability Assessment Of Power System Using Radial Basis Function Neural Network And A New Feature Extraction Method, Ahmed M. Haidar, Azah Mohamed, Aini Hussain
Vulnerability Assessment Of Power System Using Radial Basis Function Neural Network And A New Feature Extraction Method, Ahmed M. Haidar, Azah Mohamed, Aini Hussain
Faculty of Informatics - Papers (Archive)
Vulnerability assessment in power systems is important so as to determine how vulnerable a power system in case of any unforeseen catastrophic events. This paper presents the application of Radial Basis Function Neural Network (RBFNN) for vulnerability assessment of power system incorporating a new proposed feature extraction method named as the Neural Network Weight Extraction (NNWE) for dimensionality reduction of input data. The performance of the RBFNN is compared with the Multi Layer Perceptron Neural Network (MLPNN) so as to evaluate the effectiveness of the RBFNN in assessing the vulnerability of a power system based on the indices, power system …
Power Quality Survey Factor Analysis Using Multivariable Linear Regression (Mvlr), Chandana Herath, Victor J. Gosbell, Sarath Perera, David A. Stirling
Power Quality Survey Factor Analysis Using Multivariable Linear Regression (Mvlr), Chandana Herath, Victor J. Gosbell, Sarath Perera, David A. Stirling
Faculty of Informatics - Papers (Archive)
During the past two decades, there has been a considerable number of Power Quality (PQ) monitoring programs completed throughout the world. The information collected during these surveys can provide a detailed picture of the expected electrical environment help utilities to plan their future networks in relation to power quality performance. The mass of data gathered for a sample of sites of a large-scale power quality (PQ) survey of this nature has the potential to reveal good and bad influences on power quality if an appropriate procedure for analysis can be determined. If it is known which characteristics are more important …
Vulnerability Assessment Of A Large Sized Power System Considering A New Index Based On Power System Loss, Ahmed M. Haidar, Azah Mohamed, Aini Hussain
Vulnerability Assessment Of A Large Sized Power System Considering A New Index Based On Power System Loss, Ahmed M. Haidar, Azah Mohamed, Aini Hussain
Faculty of Informatics - Papers (Archive)
The concept of power system vulnerability assessment combines information on the level of system security as well as information on a wide range of situations, events and contingencies with regards to which a system is vulnerable. This paper attempts to investigate and evaluate the effect of line outage, generation outage and amount of load disconnected on the power transmission network losses of a large size power system. These effects will be investigated and evaluated using new proposed method based on vulnerability index of power system loss. The objectives of this work is to evaluate and compare the efficiency of the …
A Wireless Sensor Node Architecture Using Remote Power Charging, For Interaction Applications, Matthew D'Souza, Konstanty Bialkowski, Adam Postula, Montserrat B. Ros
A Wireless Sensor Node Architecture Using Remote Power Charging, For Interaction Applications, Matthew D'Souza, Konstanty Bialkowski, Adam Postula, Montserrat B. Ros
Faculty of Informatics - Papers (Archive)
The wireless sensor node architecture proposed inthis paper is optimized for use in a wireless interactivepoint, listen and see system. In particular, we focus ondeveloping a wireless sensor node that can beremotely charged by harvesting microwave energy.The current system implementation allows a user toaccess information from a remote sensor via theirmobile computing device. These sensors are limited incomplexity due to the limited power available, and arecumbersome since manual intervention is required toreplace its batteries. We propose a system wherebattery powered wireless sensor nodes can berecharged by harvesting energy from a microwaveRadio Frequency (RF) signal source. The remotepower charging module of …
The Power And Influence In Some Youden Squares And Secret Sharing, Lakoa Fitina, Kenneth G. Russell, Jennifer Seberry
The Power And Influence In Some Youden Squares And Secret Sharing, Lakoa Fitina, Kenneth G. Russell, Jennifer Seberry
Faculty of Informatics - Papers (Archive)
We investigate subsets of critical sets of some Youden squares in the context of secret sharing schemes. A subset C of a Youden square is called a critical set, if C can be uniquely completed to a Youden square but any subset of C cannot does not have a unique completion to a Youden square. That part of a Youden square Y which is inaccessible to subsets of a critical set C of Y, called the strongbox of C, may be thought to contain secret information. We study the size of the secret. Seberry and Street have shown how strongboxes …
New Method Vulnerability Assessment Of Power System, Ahmed M. Haidar, Azah Mohamed, Aini Hussain
New Method Vulnerability Assessment Of Power System, Ahmed M. Haidar, Azah Mohamed, Aini Hussain
Faculty of Informatics - Papers (Archive)
Vulnerability assessment in power systems is to determine a power system`s ability to continue to provide service in case of an unforeseen catastrophic contingency. It combines information on the level of system security as well as information on a wide range of scenarios, events and contingencies. To assess the level of system strength or weakness relative to the occurrence of an undesired event, a quantitative measure based on vulnerability index is often considered. In this study, a new vulnerability assessment method is proposed based on total power system loss which considers power generation loss due to generation outage, power line …
The Influence Of Site Physical Characteristics On Power Quality Performance, Glenn Nicholson, Victor J. Gosbell, Ashok Parsotam
The Influence Of Site Physical Characteristics On Power Quality Performance, Glenn Nicholson, Victor J. Gosbell, Ashok Parsotam
Faculty of Informatics - Papers (Archive)
Routine power quality (PQ) monitoring is limited to a statistical sample of sites that are hopefully representative of the overall PQ performance of the network. It would be helpful if the PQ performance of un-monitored sites could be inferred from the results of a PQ survey from a site having similar physical characteristics. This is only possible if it is known which physical characteristics are most influential in determining PQ performance. This paper describes the application of factor analysis techniques to determine the relationship between known site physical characteristics and PQ disturbance levels on the Vector Distribution Network (Auckland, New …
The Power And Influence In Some Youden Squares And Secret Sharing, L. Fitina, Ken Russell, Jennifer Seberry
The Power And Influence In Some Youden Squares And Secret Sharing, L. Fitina, Ken Russell, Jennifer Seberry
Faculty of Informatics - Papers (Archive)
We investigate subsets of critical sets of some Youden squares in the context of secret sharing schemes. A subset C of a Youden square is called a critical set, if C can be uniquely completed to a Youden square but any subset of C cannot does not have a unique completion to a Youden square. That part of a Youden square Y which is inaccessible to subsets of a critical set C of Y, called the strongbox of C, may be thought to contain secret information. We study the size of the secret. Seberry and Street have shown how strongboxes …
Assessing The Impact Of Increased Air Conditioner Load On Power Quality In Australia, Lianne Mollier, D A. Robinson, Sarath Perera, Victor J. Gosbell, Frank Bucca
Assessing The Impact Of Increased Air Conditioner Load On Power Quality In Australia, Lianne Mollier, D A. Robinson, Sarath Perera, Victor J. Gosbell, Frank Bucca
Faculty of Informatics - Papers (Archive)
Measurements of performance of existing technology air conditioner systems with regards to their impact on power quality in LV distribution systems are presented. Three types of split-phase air conditioners are studied including direct on line starting, soft starter and inverter fed units. Results of testing and subsequent calculations illustrate that the direct on line and soft starter units do not meet compliance requirements of the relevant standard, and as penetration of air conditioners increases, voltage fluctuations may become a significant problem in some LV distribution systems in Australia.
Power System Applications Of Superconducting Magnetic Energy Storage Systems, X D. Xue, Eric Kw Cheng, Danny Sutanto
Power System Applications Of Superconducting Magnetic Energy Storage Systems, X D. Xue, Eric Kw Cheng, Danny Sutanto
Faculty of Informatics - Papers (Archive)
This study overviewed current researches on power system applications of SMES systems. Some key schematic diagrams of applications were given, too. Furthermore, the authors tried to present a few valuable suggestions for future studies of SMES applications to power systems.
Further Results On Strongbox Secured Secret Sharing Schemes, G. Gamble, B. M. Maenhaut, Jennifer Seberry, A. Penfold Street
Further Results On Strongbox Secured Secret Sharing Schemes, G. Gamble, B. M. Maenhaut, Jennifer Seberry, A. Penfold Street
Faculty of Informatics - Papers (Archive)
We extend our earlier work on ways in which defining sets of combinatorial designs can be used to create secret sharing schemes. We give an algorithm for classifying defining sets of designs according to their security properties and summarise the results of this algorithm for many small designs. Finally, we discuss briefly how defining sets can be applied to variations of the basic secret sharing scheme.
Issues Affecting Power Engineering Undergraduate Education In Australia, D A. Robinson, Victor J. Gosbell
Issues Affecting Power Engineering Undergraduate Education In Australia, D A. Robinson, Victor J. Gosbell
Faculty of Informatics - Papers (Archive)
Recent changes to the electric power industry through deregulation and restructuring have had a considerable effect on power engineering education internationally. A number of Australian universities have also noticed a decline in the number of students interested in power engineering subjects, leading to the fewer graduates with power engineering knowledge. With a reduction in graduates and a perception of an aging workforce a shortage of suitably qualified power engineers for industry may be imminent. This paper provides discussion on the current status of university power engineering education within Australia and includes results from a recent Australia-wide survey of the university …
Power Quality Data Analysis Using Unsupervised Data Mining, Ali Asheibi, David A. Stirling, Sarath Perera, D A. Robinson
Power Quality Data Analysis Using Unsupervised Data Mining, Ali Asheibi, David A. Stirling, Sarath Perera, D A. Robinson
Faculty of Informatics - Papers (Archive)
The rapid increase in the size of databases required to store power quality monitoring data has demanded new techniques for analysing and understanding the data. One suggested technique to assist in analysis is data mining. Data mining is a process that uses a variety of data analysis tools to identify hidden patterns and relationships within large samples of data. This paper presents several data mining tools and techniques that are applicable to power quality data analysis to enable efficient reporting of disturbance indices and identify network problems through pattern recognition. This paper also presents results of data mining techniques applied …
Flicker Transfer In Radial Power Systems, Sankika Tennakoon, Lakshal Perera, D A. Robinson, Sarath Perera
Flicker Transfer In Radial Power Systems, Sankika Tennakoon, Lakshal Perera, D A. Robinson, Sarath Perera
Faculty of Informatics - Papers (Archive)
Loads which exhibit continuous and rapid variations in their current can cause voltage fluctuations that are often referred to as flicker. One good example for such loads is arc furnaces which are usually fed by dedicated feeders from the high voltage busbars in transmission systems. The flicker generated from such loads will propagate to the upstream HV point of common coupling (PCC), and from there to the downstream through the transmission and sub transmission systems. This paper demonstrates how the generated flicker is propagated from the HV PCC to the downstream in radial networks exhibiting different levels of attenuation depending …
Assessing The Future Of Electrical Power Engineering: A Report On Electrical Power Engineering Manpower Requirements In Australia, Victor J. Gosbell, D A. Robinson
Assessing The Future Of Electrical Power Engineering: A Report On Electrical Power Engineering Manpower Requirements In Australia, Victor J. Gosbell, D A. Robinson
Faculty of Informatics - Papers (Archive)
In 2001 the Electric Energy Society of Australia (EESA) developed concerns based on anecdotal evidence that there was a looming shortage of electrical power engineers in Australia. Information from the electrical power industry and academic communities was obtained through two separate survey questionnaires, a discussion workshop, and a number of submissions. This information was collated and compiled into 'Assessing the Future of Electrical Power Engineering: a Report on Electrical Power Engineering Manpower Requirements in Australia'.
Data Management For Large Scale Power Quality Surveys, Murray-Luke Peard, Sean T. Elphick, Victor W. Smith, Victor J. Gosbell, D A. Robinson
Data Management For Large Scale Power Quality Surveys, Murray-Luke Peard, Sean T. Elphick, Victor W. Smith, Victor J. Gosbell, D A. Robinson
Faculty of Informatics - Papers (Archive)
For large scale power quality surveys, the management of the large amount of data generated is a major issue. This paper presents solutions to three main areas of data management, viz. a data interchange format, database design and data processing. Consideration of these issues has come about as a result of the Long Term National Power Quality Survey currently being conducted by the University of Wollongong, and reference is made to that specific application for illustrative purposes.
Size And Power Considerations For Testing Loglinear Models Using Divergence Test Statistics, Noel A. Cressie, L Pardo, M Del Carmen Pardo
Size And Power Considerations For Testing Loglinear Models Using Divergence Test Statistics, Noel A. Cressie, L Pardo, M Del Carmen Pardo
Faculty of Informatics - Papers (Archive)
In this article, we assume that categorical data are distributed according to a multinomial distribution whose probabilities follow a loglinear model. The inference problem we consider is that of hypothesis testing in a loglinear-model setting. The null hypothesis is a composite hypothesis nested within the alternative. Test statistics are chosen from the general class of divergence statistics. This article collects together the operating characteristics of the hypothesis test based on both asymptotic (using large-sample theory) and finite-sample (using a designed simulation study) results. Members of the class of power divergence statistics are compared, and it is found that the Cressie-Read …
A Transient Index For Reporting Power Quality Surveys, Victor J. Gosbell, Sarath Perera, D A. Robinson, Chandana Herath
A Transient Index For Reporting Power Quality Surveys, Victor J. Gosbell, Sarath Perera, D A. Robinson, Chandana Herath
Faculty of Informatics - Papers (Archive)
Impulsive transients are often blamed for the destruction of customer appliances. Advances in Power Quality (PQ) monitors will soon make it feasible to incorporate impulsive transients into routine power quality surveys. This paper considers how the transient events captured over a period at many sites may be reported in a simple but useful manner. The paper first summarizes a recent publication by some of the authors, which attempt to give a complete framework for the analysis of utility PQ data. This framework provides a basis for evaluating existing transient characterization practices as well as for the proposed new transient index …
Use Of Cryoelectronics To Reduce Power Losses, Christopher J. Hawley, Steve Gower, Dominic Cuiuri
Use Of Cryoelectronics To Reduce Power Losses, Christopher J. Hawley, Steve Gower, Dominic Cuiuri
Faculty of Informatics - Papers (Archive)
The operational characteristics of power electronics operating at ambient temperatures are well known. Less well known are the characteristics of these devices when operating at cryogenic temperatures. This emerging field is known as cryoelectronics. The primary driver for operation at reduced temperatures is the promise of a resultant reduction in device operation losses. The operating characteristics of Metal Oxide Silicon Field Effect Transistors (MOSFETs) and Insulated Gate Bipolar Transistors (IGBTs) at Liquid Nitrogen (LN) temperature have been experimentally analysed. The results have been used to evaluate the viability of using cryoelectronics in medium - high power applications, considering trade-offs between …
Behavioural Modelling Of High Temperature Superconducting Wires And Coils For Power Engineering Applications, Thomas Hardjono, Christopher David Cook, Sarath Perera
Behavioural Modelling Of High Temperature Superconducting Wires And Coils For Power Engineering Applications, Thomas Hardjono, Christopher David Cook, Sarath Perera
Faculty of Informatics - Papers (Archive)
Many aspects of the behaviour of high temperature superconducting (HTS) wires are well understood for dc applications. However, models of HTS suitable for use in circuit analysis by power engineers designing HTS applications are not readily available. This paper describes the initial development of suitable models for HTS wire. The V-I characteristics for wires carrying dc transport current can be empirically determined using a power law V=kIn. Experimentally measured V-I characteristics are fitted using the above power law. This enables the simulation of the behaviour of Bi-2223/Ag wire using the well-known circuit simulator PSpice. Other factors affecting the dc critical …