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Full-Text Articles in Social and Behavioral Sciences
A Relaxation Strategy With Fuzzy Constraints For Supplier Selection In A Power Market, Dien Tuan Le, Minjie Zhang, Fenghui Ren
A Relaxation Strategy With Fuzzy Constraints For Supplier Selection In A Power Market, Dien Tuan Le, Minjie Zhang, Fenghui Ren
Faculty of Engineering and Information Sciences - Papers: Part A
A power market is a special kind of e-markets. In a power market, all trading processes are related to three parties: buyers, suppli- ers and brokers. A broker acts as middlemen between buyers and sup- pliers in a trading process. In a power market, how to select a potential supplier for a buyer through a broker based on the buyer's requirements is a challenging research problem. This paper proposes relaxation strat- egy with fuzzy constraints for supplier selection. The strategy includes three components, i.e., a supplier selection, a fuzzy constraint relaxation, and a decision making. The major contributions of this …
Power Sharing Among Multiple Solar Photovoltaic (Pv) Systems In A Radial Distribution Feeder, Brian K. Perera, Philip Ciufo
Power Sharing Among Multiple Solar Photovoltaic (Pv) Systems In A Radial Distribution Feeder, Brian K. Perera, Philip Ciufo
Faculty of Engineering and Information Sciences - Papers: Part A
With an increasing penetration of solar photovoltaic (PV) systems, power distribution grids are becoming more susceptible to network voltage rise. As per applicable standards for grid-integrated PV systems, a PV system must be automatically disconnected from the grid when the terminal voltage of the PV system exceeds a defined maximum voltage. With this directive, in certain situations, PV systems connected at nodes at which the voltage sensitivity is high, may be disconnected from the grid while PV systems connected at less sensitive nodes are continuing to operate. In such a situation, owners whose PV systems are connected at nodes at …
Power Quality Emission Assessment Of Photovoltaic Inverters Based On Iec Technical Report 61000-3-15:2011, Devinda Perera, Philip Ciufo, Lasantha G. Meegahapola, Sarath Perera
Power Quality Emission Assessment Of Photovoltaic Inverters Based On Iec Technical Report 61000-3-15:2011, Devinda Perera, Philip Ciufo, Lasantha G. Meegahapola, Sarath Perera
Faculty of Engineering and Information Sciences - Papers: Part A
The International Electrotechnical Committee Technical Report IEC 61000-3-15:2011 provides electromagnetic compatibility requirements and test conditions for distributed generators up to 75 A per phase. In the current research, two commercially available photovoltaic (PV) inverters up to the capacity of 3600 W were tested following the guidelines proposed in IEC 61000-3-15 in relation to low order harmonic emission and flicker emission. In addition, the harmonic and flicker emission behaviour of the PV inverters were investigated under varying irradiation conditions. Both PV inverters were observed to comply with the emission requirements prescribed by the technical report under most conditions except for even …
Estimation Of Capacity Credits For Wind Generation Plants In The South East Australian Power Grid, Md Abu Abdullah, Kashem Muttaqi, Ashish Agalgaonkar, Darmawan Sutanto
Estimation Of Capacity Credits For Wind Generation Plants In The South East Australian Power Grid, Md Abu Abdullah, Kashem Muttaqi, Ashish Agalgaonkar, Darmawan Sutanto
Faculty of Engineering and Information Sciences - Papers: Part A
It is important to estimate the contribution of the wind generation plants in the evaluation of system generation adequacy for power generation planning. Australia has recently proposed to utilize the diversity of the wind energy resources in Southeast Australian power grid through existing inter-State interconnections. This paper aims to present a probabilistic adequacy model for the capacity credit estimation of wind generation plants in interconnected power systems. In particular, the proposed adequacy model will be applied to investigate how sharing of wind energy resource diversity can enhance the capacity credit of the wind generation plants. The impact of the inter-tie …
Comparative Analysis Of Dynamic Line Rating Models And Feasibility To Minimise Energy Losses In Wind Rich Power Networks, Mathew Simms, Lasantha Meegahapola
Comparative Analysis Of Dynamic Line Rating Models And Feasibility To Minimise Energy Losses In Wind Rich Power Networks, Mathew Simms, Lasantha Meegahapola
Faculty of Engineering and Information Sciences - Papers: Part A
Wind power generation has indicated an exponential increase during last two decades and existing transmission network infrastructure is increasingly becoming inadequate to transmit remotely generated wind power to load centres in the network. The dynamic line rating (DLR) is one of the viable solutions to improve the transmission line ampacity during high wind penetration without investing on an additional transmission network. The main objective of this study is to identify the basic differences between two main line rating standards, since transmission network service providers (TNSPs) heavily depend on these two standards when developing their line rating models. Therefore, a parameter …
On The Management Of Wind Power Intermittency, Ehsan Rahimi, Abdorreza Rabiee, Jamshid Aghaei, Kashem Muttaqi, Ali Esmaeel Nezhad
On The Management Of Wind Power Intermittency, Ehsan Rahimi, Abdorreza Rabiee, Jamshid Aghaei, Kashem Muttaqi, Ali Esmaeel Nezhad
Faculty of Engineering and Information Sciences - Papers: Part A
Nowadays, the world is encountering severe challenges in the energy generation sector. Environmental issues like climate change, global warming and Green House Gases (GHGs) and also social issues like dramatic increase in global population and increasing energy demand are the main causes of global concerns about energy resource management. In this regard, Renewable Energy Sources (RESs) are the suitable substitution to replace the conventional generating units that emit GHGs due to the use of fossil fuels. Among all RESs, wind energy seems to be promising for generating emission-free electrical energy. However, it is naturally unpredictable due to its intermittency which …
Power-Aware Routing In Networks With Delay And Link Utilization Constraints, Gongqi Lin, Sieteng Soh, Mihai Lazarescu, Kwan-Wu Chin
Power-Aware Routing In Networks With Delay And Link Utilization Constraints, Gongqi Lin, Sieteng Soh, Mihai Lazarescu, Kwan-Wu Chin
Faculty of Engineering and Information Sciences - Papers: Part A
Current network infrastructures are over-provisioned and thus exhibit poor power efficiency at low traffic load. In this paper, we consider networks comprising of bundled links, whereby each link has one or more physical cables that can be switched off independently. The problem at hand is then to switch off redundant cables during off peak periods, while retaining the QoS provided to existing traffic demands. Unfortunately, the problem to maximally shutdown redundant cables is an NP-complete problem. Henceforth, we design a fast heuristic, called Multiple Paths by Shortest Path First (MSPF), that aims to maximize the number of switched-off cables subject …
Voltage Security Constrained Reactive Power Optimization Incorporating Wind Generation, L G. Meegahapola, E Vittal, A Keane, D Flynn
Voltage Security Constrained Reactive Power Optimization Incorporating Wind Generation, L G. Meegahapola, E Vittal, A Keane, D Flynn
Faculty of Engineering and Information Sciences - Papers: Part A
This paper presents a comparative analysis between conventional optimal power flow (OPF) and voltage constrained OPF strategies with wind generation. The study has been performed using the New England 39 bus system with 12 doublyfed induction generator (DFIG) based wind farms installed across the network. A voltage security assessment is carried out to determine the critical wind farms for voltage stability enhancement. The power losses and individual wind farm reactive power generation have been compared with and without voltage stability constraints imposed on the OPF simulation. It is shown that voltage constrained OPF leads to much greater active power losses …
Application Of Multi-Agent System For Preventing Power Interruption In A Large Power System, S R. Islam, Darmawan Sutanto, K M. Muttaqi
Application Of Multi-Agent System For Preventing Power Interruption In A Large Power System, S R. Islam, Darmawan Sutanto, K M. Muttaqi
Faculty of Engineering and Information Sciences - Papers: Part A
This paper presents an emergency control approach for preventing wide spread power interruption using multi-agent system. The proposed control algorithm is based on decentralized architecture of intelligent agents to achieve fast and accurate response when a catastrophic disturbance is identified in the system. By dividing the network into several areas, the voltage instability problem can be localized and countermeasures can be directed to the most affected area by the authorized local agent. This facilitates quick decision making within the system. The effectiveness of the proposed technique has been proved by a simulation of IEEE 57 bus test power system.
Characteristics Of Power Quality Disturbance Levels In Australia, Sean Elphick, Vic Smith, Vic Gosbell, Robert Barr
Characteristics Of Power Quality Disturbance Levels In Australia, Sean Elphick, Vic Smith, Vic Gosbell, Robert Barr
Faculty of Engineering and Information Sciences - Papers: Part A
The Australian Long Term Power Quality Survey (LTNPQS) now covers 2,000 sites with a range of different characteristics including strength (related to fault level), line construction and dominant load type. This paper details the latest outcomes of the LTNPQS project in terms of both disturbance levels and reporting methods. A comparison of the differences between voltage, unbalance and harmonic THD levels at strong (close to transformer) and weak (towards the end of LV feeders) sites has been performed and significant differences have been found. A multivariable linear regression study has been undertaken in order to investigate the correlation between site …
Sax-Based Decomposition Of Non-Stationary Power Quality Waveforms, M J. Afroni, Darmawan Sutanto, D Stirling
Sax-Based Decomposition Of Non-Stationary Power Quality Waveforms, M J. Afroni, Darmawan Sutanto, D Stirling
Faculty of Engineering and Information Sciences - Papers: Part A
The Hilbert Huang Transform (HHT) is a powerful tool for Power Quality (PQ) classifications. One of the main advantages of the HHT is its ability to analyze non-stationary complex waveforms with very good time resolution. However, like other waveform classification techniques, it has difficulty in resolving the instant of sudden changes in the waveform. To overcome the above problems, SAX (Symbolic Aggregate ApproXimation) method is proposed to convert the signal into symbols which facilitates a pattern detector algorithm to identify the border of the stationary signals within a non-stationary signal. Results from simulations will be provided and discussed. © 2012 …
Voltage Unbalance Management In Power Systems Based On Iec 61000-3-13:2008: Implications On The Use Of 'Kue Factor', Upuli Jayatunga, Sarath Perera, Philip Ciufo
Voltage Unbalance Management In Power Systems Based On Iec 61000-3-13:2008: Implications On The Use Of 'Kue Factor', Upuli Jayatunga, Sarath Perera, Philip Ciufo
Faculty of Engineering and Information Sciences - Papers: Part A
Voltage unbalance emission allocation principles prescribed in IEC61000-3-13:2008 Technical Report utilise a factor, kuE, which allows separation of the total voltage unbalance that arises at a point of evaluation due to both the load under consideration and the supply network. As per the definition given, this factor (kuE) accounts for the unbalance emission that arises due to the load whereas (1-kuE) accounts for unbalance that arises due to the network. The technical report prescribes a range of values from which a suitable value can be chosen based on the system characteristics, however, no systematic methodologies exist to-date to determine the …
Hybrid Power Saving Technique For Wireless Sensor Networks, Asama Alshaibi, Peter Vial, Montserrat Ros
Hybrid Power Saving Technique For Wireless Sensor Networks, Asama Alshaibi, Peter Vial, Montserrat Ros
Faculty of Engineering and Information Sciences - Papers: Part A
In wireless communication, idle listening, receiving and transmitting are the main source of consumption of energy. This paper gives an overview of several techniques used for wireless networks. We incorporated PSM and PC to gain the advantage of PSM (reduce idle listening) and PC (reduce receiving and transmitting power) and implemented them in the IEEE 802.15.4 protocol. The results show that the new hybrid technique saves more power than PSM and PC individually. © 2012 IEEE.
Robust And Intelligent Control Methods To Improve The Performance Of A Unified Power Flow Controller, C Benachaiba, Ahmed M. Haidar, M L. Doumbia
Robust And Intelligent Control Methods To Improve The Performance Of A Unified Power Flow Controller, C Benachaiba, Ahmed M. Haidar, M L. Doumbia
Faculty of Engineering and Information Sciences - Papers: Part A
The important factor disturbing the modern power systems today is load flow control. The Unified Power Flow Controller (UPFC) is an effective way for controlling the power flow and can provide damping capability during transient conditions. The UPFC is controlled conventionally using PI controller. This paper presents two robust controllers to improve the performance of the UPFC. The first is a RST controller based on the principle of pole placement and the second is an intelligent controller based on the principle of fuzzy logic optimized by Genetic Algorithm (GA).
Superposition Coded Modulation With Peak-Power Limitation, Jun Tong, Li Ping, Xiao Ma
Superposition Coded Modulation With Peak-Power Limitation, Jun Tong, Li Ping, Xiao Ma
Faculty of Engineering and Information Sciences - Papers: Part A
We apply clipping to superposition coded modulation (SCM) systems to reduce the peak-to-average power ratio (PAPR) of the transmitted signal. The impact on performance is investigated by evaluating the mutual information driven by the induced peak-power-limited input signals. It is shown that the rate loss is marginal for moderate clipping thresholds if optimal encoding/decoding is used. This fact is confirmed in examples where capacityapproaching component codes are used together with the maximum a posteriori probability (MAP) detection. In order to reduce the detection complexity of SCM with a large number of layers, we develop a suboptimal soft compensation (SC) method …
Performance Analysis Of Ofdm-Idma Systems With Peak-Power Limitation, Jun Tong, Qinghua Guo, Li Ping
Performance Analysis Of Ofdm-Idma Systems With Peak-Power Limitation, Jun Tong, Qinghua Guo, Li Ping
Faculty of Engineering and Information Sciences - Papers: Part A
This paper is concerned with orthogonal frequency-division multiplexing interleave-division multiple-access (OFDM-IDMA) systems over frequency-selective fading channels. Deliberate clipping is applied to reduce the peak-to-average power ratio (PAPR) of each user's transmitted signal. An iterative multiuser detection (MUD) technique is developed to recover the performance loss due to clipping. A semi-analytical signal-to- noise ratio (SNR) evolution technique is proposed, which can provide quick and accurate prediction of the iterative MUD performance. Numerical results show that the performance of OFDM-IDMA is not sensitive to the frequency selectivity of channels, and OFDM-IDMA is more power-efficient than other alternative multi-carrier transmission techniques. © 2008 …
Loading Capabilities Assesment Of Power Transmission Lines, P Hu, Michael Negnevitsky, Kashem M. Muttaqi
Loading Capabilities Assesment Of Power Transmission Lines, P Hu, Michael Negnevitsky, Kashem M. Muttaqi
Faculty of Engineering and Information Sciences - Papers: Part A
This paper reviews the factors that affect the loading capabilities of the transmission line over the short duration. The paper demonstrates how to determine the impact of various parameters on the permissible loading of bare conductors of a power transmission line. Methods for calculating these factors are presented. A sample of a practical application is also included in order to show how these factors affect the loading capabilities of a transmission line.
Distributed Generation For Minimization Of Power Losses In Distribution Systems, Kashem M. Muttaqi, An D. T Le, Michael Negnevitsky, Gerard Ledwich
Distributed Generation For Minimization Of Power Losses In Distribution Systems, Kashem M. Muttaqi, An D. T Le, Michael Negnevitsky, Gerard Ledwich
Faculty of Engineering and Information Sciences - Papers: Part A
Appropriate size and location of distributed generation (DG) play a significant role in minimizing power losses in distribution systems. This paper represents techniques to minimize power losses in a distribution feeder by optimizing DG model in terms of size, location and operating point of DG. Sensitivity analysis for power losses in terms of DG size and DG operating point has been performed. The proposed sensitivity indices can indicate the changes in power losses with respect to DG current injection. The proposed techniques have been developed with considering load characteristics and representing loads with constant impedance and constant current models, separately. …
Minimising Power Losses In Distribution Systems With Distributed Resources, An D. T Le, Kashem M. Muttaqi, Michael Negnevitsky, Gerard Ledwich
Minimising Power Losses In Distribution Systems With Distributed Resources, An D. T Le, Kashem M. Muttaqi, Michael Negnevitsky, Gerard Ledwich
Faculty of Engineering and Information Sciences - Papers: Part A
Attempts to reduce electricity cost, together with improving the efficiency of distribution systems, have led power utilities to dealing with the problem of power loss minimisation. Although losses in the system can never be entirely eliminated, they can be controlled and minimised in several ways. Research conducted in the last few decades has proven that an inclusion of Distributed Resources (DR) into distribution systems considerably lowers the level of power losses. Moreover, the choice of DR is even more attractive since it provides not only benefits in power loss minimisation, but also a wide range of other advantages including environment, …
Dynamics Of A Hydro-Wind Hybrid Isolated Power System, M Aktarujjaman, Kashem M. Muttaqi, Michael Negnevitsky, Gerard Ledwich
Dynamics Of A Hydro-Wind Hybrid Isolated Power System, M Aktarujjaman, Kashem M. Muttaqi, Michael Negnevitsky, Gerard Ledwich
Faculty of Engineering and Information Sciences - Papers: Part A
Implementation of Distributed Generation (DG) can improve power quality and reliability, and guarantee continuity of power supply. This paper addresses the issue of continuity of power supply especially for isolated communities. A part of a network can be electrically isolated from the main grid when the grid fails to supply power due to a fault in the network or unavailability of power generation. In this paper, a mini hydro-wind hybrid power system is considered, and operation and control of the hybrid system during connecting it with the grid as well as its operation in the isolated condition are investigated. The …
Issues For Connection Of Distributed Generation In Rural/Remote Power Systems, Kashem M. Muttaqi, Gerard Ledwich, Michael Negnevitsky
Issues For Connection Of Distributed Generation In Rural/Remote Power Systems, Kashem M. Muttaqi, Gerard Ledwich, Michael Negnevitsky
Faculty of Engineering and Information Sciences - Papers: Part A
Connection of distributed generation (DG) into a distribution grid system affects the normal operation, control and protection of the distribution system. This paper addresses some of the technical issues arisen due to the addition of generation to a rural/remote distribution network. In this paper, a voltage controlled rotary DG is modelled to operate in the line of voltage sensitivity for maximum voltage improvement. A scenario-based study on DG operation and control has been conducted and recommendations for effective operation of DG presented. An investigation on barriers to inclusion of utility owned and customer owned DG has been carried out and …