http://hdl.handle.net/10468/130 2013-05-22T22:54:38Z http://hdl.handle.net/10468/1010 How much wind energy will be curtailed on the 2020 Irish power system? McGarrigle, E. V.; Deane, J. P.; Leahy, Paul G. This paper describes a model of the 2020 Irish electricity system which was developed and solved in a mixed integer programming, unit commitment and economic dispatch tool called PLEXOS. The model includes all generators on the island of Ireland, a simplified representation of the neighbouring British system including proposed wind capacity and interconnectors between the two systems. The level of wind curtailment is determined under varying levels of three influencing factors. The first factor is the amount of offshore wind, the second is the allowed limit of system non-synchronous penetration (SNSP) and the third is inclusion or exclusion of transmission constraints. A binding constraint, resulting from the 2020 EU renewable energy targets, is that 37% of generation comes from wind. When the SNSP limit was increased from 60% to 75% there was a reduction in wind curtailment from 14% to 7%, with a further reduction when the proportion of wind capacity installed offshore was increased. Wind curtailment in the range of SNSP limit of 70-100% is influenced primarily by the inclusion of transmission constraints. Large changes in the dispatch of conventional generators were also evident due to the imposition of SNSP limits and transmission constraints. 2013-07-01T00:00:00Z http://hdl.handle.net/10468/719 A normalization-based approach to the mobility analysis of spatial compliant multi-beam modules Hao, Guangbo; Kong, Xianwen This paper presents a normalization-based approach to the mobility analysis of spatial compliant multi-beam modules to address the dimensional-inhomogeneity issue of motion/load. Firstly, two spatial non-tilted and tilted multi-beam modules, composed of uniform beams with symmetrical cross sections and same length, are proposed. Using a normalization technique, the compliance matrices of these spatial multi-beam modules are derived, from which the DOF (degrees-of-freedom) of the compliant modules can be obtained by direct observation and/or screw representation. The results are compared with those obtained without normalization. It is shown that the DOF of these compliant modules can be identified more easily using the proposed approach than the approach without normalization. Then, two spatial double non-tilted and tilted three-beam modules are proposed and analyzed for potential applications such as acting as building blocks of new compliant manipulators. The normalization-based approach can also be used for the mobility analysis of spatial compliant multi-sheet modules such as the parallelogram module and the four-sheet rotational module and the error analysis of spatial multi-beam modules with beams of compatible length. 2013-01-01T00:00:00Z http://hdl.handle.net/10468/1057 Fast and accurate approximations for the analysis of energy detection in Nakagami-m channels Horgan, Donagh; Murphy, Colin C. Previous research has identified several exact methods for the evaluation of the probability of detection for energy detectors operating on Nakagami-m faded channels. However, these methods rely on discrete summations of complicated functions, and so can take a prohibitively long time to evaluate. In this paper, three approximation for the probability of detection in Nakagami-m faded channels, having distinct regions of applicability, are derived. All have closed forms, and enable the fast and accurate computation of key performance metrics. 2013-01-01T00:00:00Z http://hdl.handle.net/10468/411 Nonlinear penalties in dynamic optical networks employing autonomous transponders Rafique, Danish; Ellis, Andrew D. We report for the first time on the limitations in the operational power range of network traffic in the presence of heterogeneous 28-Gbaud polarization-multiplexed quadrature amplitude modulation (PM-mQAM) channels in a nine-channel dynamic optical mesh network. In particular, we demonstrate that transponders which autonomously select a modulation order and launch power to optimize their own performance will have a severe impact on copropagating network traffic. Our results also suggest that altruistic transponder operation may offer even lower penalties than fixed launch power operation 2011-09-01T00:00:00Z