Engineering Commons^™

Analysis Of Converter Connected Synchronous Wind Turbines To Grid Disturbances., Joseph Kearney, Michael Conlon, Eugene Coyle

Conference papers

This paper investigates the performance of synchronous generators to grid voltage unbalance and grid faults. A Model of a synchronous generator with a full converter is implemented in the SimPowerSystems toolbox in Matlab/Simulink. Methods to modify the converter control schemes to improve the synchronous generator systems response to grid voltage unbalance and grid faults are investigated. Grid faults including grid voltage unbalance, and line-to-ground faults are introduced into the model at specific times to analyse the performance of the wind generation system. Improvements in the performance of the synchronous generator WECS to the grid disturbances are illustrated.

A Review Of Parallel Operation Of Active Power Filters In The Distributed Generation System, Shafiuzzaman Khan Khadem, Malabika Basu, Michael Conlon

Conference papers

In this paper a technical review of parallel operation of Active Power Filter (APF) for harmonic power compensation in distributed generation (DG) network has been presented. Controlling methods and connection topologies with their pros and cons are described. Recent improvements in controlling and future trends for the application of APFs in distributed mode are also identified.

Observations Of The Wind Resource Across The Dublin Urban Area, Keith Sunderland, Michael Conlon, Gerald Mills, Rowan Feely

Conference papers

This paper presents an investigation of wind observations made at three (of a network of ten) stations in Dublin. Two of the stations are located over different parts of the urbanized landscape and one is located at Dublin Airport, which exemplifies a typical meteorological station. The purpose of the analysis is to evaluate the nature of the wind resource in the urban area. The potential output of a range of commercially available micro wind turbines at one of the stations is considered. At this location, an anemometer is mounted in a similar manner to international examples of building mounted domestic …

Does A Link Exist Between Examination Performance And Lecture Attendance For First Year Engineering Students ?, Aidan O'Dwyer

Conference papers

The objective of this study is to examine if a link exists between lecture attendance and examination performance of Level 7, Year 1, Electrical Engineering students at Dublin Institute of Technology in the Electrical Systems subject. Lecture attendance was monitored and analysed over four academic years (2007-8, 2008-9, 2009-10 and 2010-11). The average lecture attendance for students in the three academic years from 2007-10 was 55%, increasing noticeably in the 2009-10 academic year. A statistically significant weakly positive correlation between lecture attendance and examination performance was established. Each 10% increase in student attendance at lectures improved both Module 1 examination …

Upmixing From Mono : A Source Separation Approach, Derry Fitzgerald

Conference papers

We present a system for upmixing mono recordings to stereo through the use of sound source separation techniques. The use of sound source separation has the advantage of allowing sources to be placed at distinct points in the stereo field, resulting in more natural sounding upmixes. The system separates an input signal into a number of sources, which can then be imported into a digital audio workstation for upmixing to stereo. Considerations to be taken into account when upmixing are discussed, and a brief overview of the various sound source separation techniques used in the system are given. The effectiveness …

Shifted Nmf Using An Efficient Constant-Q Transform For Monaural Sound Source Separation, Rajesh Jaiswal, Derry Fitzgerald, Eugene Coyle, Scott Rickard

Conference papers

Non-negative Matrix Factorisation (NMF) based algorithms have found application in monaural audio source separation due to their ability to factorize audio spectrogram into additive part-based basis functions, which typically corresponds to individual notes or chords in music. These separated basis functions are usually greater in number than the active sources, hence clustering is needed for individual source signal synthesis. Although, many attempts have been made to improve the clustering of the basis functions to sources, much research is still required in this area. Recently, Shifted NMF based methods have been proposed as a means to avoid clustering these pitched basis …

User Assisted Source Separation Using Non-Negative Matrix Factorisation, Derry Fitzgerald

Conference papers

Much research has been carried out on the use of non-negative matrix factorisation for the purpose of musical sound source separation. However, a notable shortcoming of non-negative matrix factorisation is that the recovered basis functions have to be clustered to sound sources for separation to take place. This has proved to be a difficult problem to solve. As a means of overcoming this problem, we introduce an extension to non-negative matrix factorisation which allows a user to guide the sepa- ration by singing, or playing along with, the source they want to separate. This is done through the use of …

Investigation Of Wave Farm Electrical Network Configurations, Fergus Sharkey, Michael Conlon, Kevin Gaughan

Conference papers

Wave Energy Converters (WECs) have been in development for a number of decades and some devices are now close to becoming a commercial reality. As such, pilot projects are being developed, particularly in the UK and Ireland, to deploy WECs on a pre-commercial array scale. There is little experience in the wave energy or utility industry of designing and installing electrical networks for WEC arrays with the closest comparison being offshore wind farms. There are some key features of WECs which will ultimately dictate thatthe electrical configuration differs from that of offshore wind farms.

This paper investigates the potential representative …

A Discussion Of Anti-Islanding Protection Schemes Incorporated In A Inverter Based Dg, Mohamed Moin Hanif, Malabika Basu, Kevin Gaughan

Conference papers

The discussion in this paper is about the local anti-islanding protection techniques that are incorporated in a inverter based DG. The most widely used passive and active techniques along with their suitability to reduce the Non-detection zone (NDZ) are explained here. The most recent work using wavelet transform which actually reduces the NDZ to zero is also introduced in the last section of the paper.

Touch2query Enabled Mobile Devices: A Case Study Using Openstreetmap And Iphone, Junjun Yin, James Carswell

Conference papers

This paper describes our mobile spatial interaction (MSI) prototype Touch2Query which presents the idea of using the touch screen on mobile devices to assist in performing ad-hoc spatial queries. This approach differs from conventional mobile LBS applications where the query shape (search space) is limited to either a bounding box or radius. Instead, we provide functionality that allows users to interactively draw any desired query shape overlaid on an area of interest directly on a mobile device with their finger by combining vector primitives such as circles, polygons, polylines, and points. With the help of location and orientation aware mobile …

Clustering Nmf Basis Functions Using Shifted Nmf For Monaural Sound Source Separation, Rajesh Jaiswal, Derry Fitzgerald, Dan Barry, Eugene Coyle, Scott Rickard

Conference papers

Non-negative Matrix Factorization (NMF) has found use in single
channel separation of audio signals, as it gives a parts-based decom-
position of audio spectrograms where the parts typically correspond
to individual notes or chords. However, a notable shortcoming of
NMF is the need to cluster the basis functions to their sources af-
ter decomposition. Despite recent improvements in algorithms for
clustering the basis functions to sources, much work still remains to
further improve these algorithms. To this end we present a novel
clustering algorithm which overcomes some of the limitations of
previous clustering methods. This involves the use of Shifted …

Weak Gradient Inverse Scattering Solutions, Jonathan Blackledge

Conference papers

The paper briefly reviews formal methods and associated conditions for solving the forward and inverse Schrodinger ¨ scattering problem for a three-dimensional elastic scattering potential. These methods are based on an application of the Green’s function and are conditional upon the properties of the scattering potential, e.g. that the scattering potential is a ‘weak scatterer’. In this paper, we explore an alternative route to solving the problem which depends on properties imposed on the scattered wavefield rather than the scattering potential. In particular, we explore the case when the gradient of the scattered wavefield is weak relative to its frequency. …

Magnetic Resonance Image Processing Using Levy Distributed Anisotropic Diffusion, Jonathan Blackledge, Matthew Blackledge

Conference papers

We consider the physical nature of the self-diffusion of water molecules in tissue and explore how (Nuclear) Magnetic Resonance (MR) imaging may be used as a means of measuring the rate of diffusion in vivo. A discussion is presented on how these techniques may be implemented as a non-invasive means of assessing the response of tumours to novel therapeutics including some of the basic advantages and disadvantages when compared to other methods. The physical basis and mathematical models for diffusion are considered together with models for the distribution of the diffusion co-efficient including a Levy distributed model. Using a …

Dynamic Electrical Ratings And The Economics Of Capacity Factor For Wave Energy Converter Arrays, Fergus Sharkey, Elva Bannon, Michael Conlon, Kevin Gaughan

Conference papers

Wave Energy Converters (WECs) have been in development for several decades with some devices now coming close to commercial realities. As such, pilot projects are being developed, particularly in the UK and Ireland, to deploy WECs on a pre-commercial array scale. The ultimate ambition is to have multiple WECs installed in a ‘wave farm’ in a similar fashion to offshore wind farms. For large scale wind farms the inter-array and export electrical systems can represent more than 20% of the project’s capital expenditure. Submarine power cables account for a large proportion of this cost. The same is expected to hold …