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Full-Text Articles in Physical Sciences and Mathematics

Optimisation Of Component Sizes For A Hybrid Remote Area Power Supply System, Saad M. Sayeef, Nishad Mendis, Kashem Muttaqi Jan 2009

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 …


Support Of Distribution System Using Distributed Wind And Pv Systems, Kai Zou, Ashish P. Agalgaonkar, Kashem Muttaqi, Sarath Perera, N Browne Jan 2009

Support Of Distribution System Using Distributed Wind And Pv Systems, Kai Zou, Ashish P. Agalgaonkar, Kashem Muttaqi, Sarath Perera, N Browne

Faculty of Informatics - Papers (Archive)

The application of renewable distributed generation (DG) could be considered as an alternative approach for distribution system expansion planning not only to reduce power loss and carbon emission, but also to improve system voltage profile. This paper investigates technical aspects relatedto voltage support and loss reduction in distribution systems with distributed wind and solar generation. The probabilistic wind, solar, and load models have been developed in order to address uncertain nature of wind speed, solar radiation, and load demand. Investigations have been carried out using Monte Carlo based probabilistic load flow analysis to estimate the probability distributions of system state …


Voltage Quality Behaviour Of A Wind Turbine Based Remote Area Power System, Nishad Mendis, Kashem Muttaqi, Sarath Perera Jan 2009

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 …


Dynamic Modelling Of Hydroelectric Turbine-Generator Unit Connected To A Hvdc System For Small Signal Stability Analysis, Yin Chin Choo, Ashish P. Agalgaonkar, Kashem Muttaqi, Sarath Perera, Michael Negnevitsky Jan 2009

Dynamic Modelling Of Hydroelectric Turbine-Generator Unit Connected To A Hvdc System For Small Signal Stability Analysis, Yin Chin Choo, Ashish P. Agalgaonkar, Kashem Muttaqi, Sarath Perera, Michael Negnevitsky

Faculty of Informatics - Papers (Archive)

This paper presents the linearised small-signal dynamic modelling of hydroelectric turbine-generator (TG) unit with CIGRE first high-voltage direct current (HVDC) benchmark system in the synchronously rotating D-Q reference frame for small-signal stability analysis. The interaction behaviour between the hydroelectric unit and the dynamics and control of HVDC system is investigated utilising eigen-analysis,participation factor analysis and by conducting sensitivity studies. The computation of eigenvalues and eigenvectors for small signal stability analysis provides an invaluable insight onto the power system dynamic behaviour by characterising the damping and frequency of the system oscillatory modes. Theconsequences of different operating conditions, such as active and …


A Car Detection System Based On Hierarchical Visual Features, Fok Hing Chi Tivive, Abdesselam Bouzerdoum Jan 2009

A Car Detection System Based On Hierarchical Visual Features, Fok Hing Chi Tivive, Abdesselam Bouzerdoum

Faculty of Informatics - Papers (Archive)

In this paper, we address the problem of detecting and localizing cars in still images. The proposed car detection system is based on a hierarchical feature detector in which the processing units are shunting inhibitory neurons. To reduce the training time and complexity of the network, the shunting inhibitory neurons in the first layer are implemented as directional nonlinear filters, whereas the neurons in the second layer have trainable parameters. A multi-resolution processing scheme is implemented so as to detect cars of different sizes, and to reduce the number of false positives during the detection stage, an adaptive thresholding strategy …


Multiresonator-Based Chipless Rfid System For Low-Cost Item Tracking, Stevan Preradovic, Isaac Balbin, Nemai Karmakar, Gerhard F. Swiegers Jan 2009

Multiresonator-Based Chipless Rfid System For Low-Cost Item Tracking, Stevan Preradovic, Isaac Balbin, Nemai Karmakar, Gerhard F. Swiegers

Faculty of Science - Papers (Archive)

A fully passive printable chipless RFID system is presented. The chipless tag uses the amplitude and phase of the spectral signature of a multiresonator circuit and provides I : 1 correspondence of data bits. The tag comprises of a microstrip spiral multiresonator and cross-polarized transmitting and receiving microstrip ultra-wideband disc loaded monopole antennas. The reader antenna is a log periodic dipole antenna with average 5.5-dBi gain. Firstly, a 6-bit chipless tag is designed to encode 000000 and 010101 IDs. Finally, a 35-bit chipless tag based on the same principle is presented. The tag has potentials for low-cost item tagging such …


Development And Application Of A System For The Analysis Of Atmospheric, Water And Sediment Nitrogen And Carbon, Ann Stavert, Stephen R. Wilson, Dianne F. Jolley Jan 2009

Development And Application Of A System For The Analysis Of Atmospheric, Water And Sediment Nitrogen And Carbon, Ann Stavert, Stephen R. Wilson, Dianne F. Jolley

Faculty of Science - Papers (Archive)

Eutrophication and climate change, key environmental concerns, are both linked to the carbon and nitrogen cycles hence the improved understanding of these cycles is essential. Currently, there is no system that simultaneously measures the fluxes of the three key gas phase products of nitrogen and carbon cycling (CO2, CH4 and N2O) in submerged ecosystems with hourly time resolution. A “Lake-in-a-box” (mesocosm) was developed in the laboratory which allowed the monitoring of key components of the carbon and nitrogen cycles within the air, water and sediments. The approach is automated, simple and time efficient and novel in its ability to examine …