In order to achieve binding Government targets towards the decarbonisation of the electricity network, the GB power system is undergoing an unprecedented amount of change. A series of new technologies designed to integrate massive volumes of renewable generation, predominantly in the form of offshore wind, asynchronously connecting to the periphery of the transmission system, are transforming the requirements of the network. This displacement of traditional thermal generation is leading to a significant reduction in system inertia, thus making the task of system operation more challenging. It is therefore deemed necessary to develop tools and technologies that provide far greater insight into the state of the power system in real-time and give rise to methods for improving offline modelling practices through an enhanced understanding of the systems performance. To that extent PMUs are seen as one of the key enablers of the Smart Grid, providing accurate time-synchronised measurements on the state of the power system, allowing the true dynamics of the power system to be captured and analysed. This thesis provides an analysis of the existing PMU deployment on the GB transmission system with a view to the future system monitoring requirements. A critical evaluation and comparison is also provided on the suitability of a University based Low Voltage PMU network to further enhance the visibility of the GB system. In addition a novel event detection algorithm based on Detrended Fluctuation Analysis is developed and demonstrated, designed to determine the exact start time of a transmission event, as well as the suitability of such an event for additional transmission system analysis, namely inertia estimation. Finally, a reliable method for the estimation of total system inertia is proposed that includes an estimate of the contribution from residual sources, of which there is currently no visibility. The proposed method identifies the importance of regional inertia and its impact to the operation of the GB transmission system.

published_or_final_version / Business Administration / Master / Master of Business Administration

Generally  cameras  are  used  for  area  based  surveillance,  but  with  advancement  in  technology, cameras  can  be  employed  for wide  area  space  surveillance  (volumetric space surveillance). The volumetric systems require a number of cameras in order to cover a large area. Single panoramic cameras  do  not  provide  required  functionality  for  wide  area  space  surveillance  and Pan-Tile-Zoom (PTZ) cameras do not either cover wide areas.   To  meet  this challenge,  we  propose  a  cost  effective smart volumetric  surveillance system  which utilizes smaller number of cameras in order to provide a coverage of 360 degree. A test case used for this system includes detection of birds in the wind farms. The proposed approach provides a solution  for recording/preventing collision  of  birds  with  wind turbine. To  realize  the  system, a model is developed with two camera nodes. This model provides a 360 degree conical volumetric space coverage. The  system is  utilizing  a  servo  motor  with  capability  of  changing  speed  and arduino  embedded  platform for  controlling  different  functionality. After  triggering  the  camera nodes from arduino, software perform the image analysis.  This  cost  effective  and  wide  area  surveillance  system  consumes at  least half lower  power as compared  to traditional  linear  systems with  eight  cameras. It  is  worth  noting  that  the system provides  conical  shaped  area coverage  of  200  square  meters  with  height ranging  from approximately 40 to 100 meters. The system would capture images in raw format in local storage and  the test  results  show  that  saving  images  with  PNG  format  requires a small  memory  size  as compared  to BMP  and TIFF.    Experiment  results  indicate  that  surveillance  system  can  be effectively employed for detecting birds in opening places.

M.B.A. / Electronic Data Systems (EDS) Africa is part of EDS International, one of the largest outsourcing companies in the world. EDS's clients expect EDS to have the required knowledge and decision-making skills to ensure that their Wide area NETWORK (WAN) redundancy is in line with the business requirement. This is a careful balance between spending money on redundancy compared with the cost of WAN downtime to the business. This implies that EDS's management must realise when the WAN design is not optimal. A decision must then be made to change the design to incorporate the correct redundancy. EDS Africa incurs substantial costs related to services supplied by Telkom (the only Telecommunication company allowed to rent WAN data lines to customers in South Africa at this point in time. They are owned by the government.). At present EDS is unable to measure Telkom's up-times using proper historical data, and using applied business statistics. (Tony Webster, 1998). Telkom does not provide EDS with any service level guarantees. When a company out-sources business to EDS, the two parties usually sign a Service Level Agreement (SLA). This agreement will state the network up-time and conditions of conducting business between the two parties. EDS generally excludes Telkom problems from the SLA, as they cannot be held responsible for problems that are outside of their control...

Recent developments in data packets based high speed digital communications have opened the door for new types of applications in power system protection and control. Intelligent Electronic Devices (IEDs) are equipped with various communication capabilities that make their functional integration a natural next step. Existing integration of substation equipment is not capable of clustering with the purpose of pooling hardware resources. <p> Presently, every electric device requiring protection has its dedicated hardware performing the predetermined set of protective functions. A new function-based protection and control philosophy is proposed, based on an open-system solution. In the proposed system, the resources of the protective and control hardware are pooled, and as a clustered system provide each protected unit (line, transformer, breaker, etc) with functions required for complete direct and backup protection. <p> The work presented in this thesis identifies the performance requirements of a digital relaying algorithm for processing samples that are sent across Ethernet-based communication channels. The work shows the shortcomings and unstable performance of widely used protective algorithms in accommodating data samples that are out of step from their proper position due to variable time delays of the communications media. A new digital relaying algorithm was developed that is able to extract the amplitude and phase angle of signals from data samples received across Ethernet networks with variable jitter. <p> The performance of the algorithm was tested by using the recovered phasor amplitude and phase angle information in protective solutions. The results show that there is significant flexibility in the algorithm that can be used to facilitate less performant communication channels, or, to take advantage of faster communications channels by reducing the response time of the protective function. <p> The results show that the algorithm works well with variable length data windows, and variable sampling frequencies. Higher sampling rates make communications problems more visible, but the presented algorithm is able to compensate for wide variations in network performance, effectively maintaining sampled signal phase and amplitude information during network performance fluctuations.

Recent developments in data packets based high speed digital communications have opened the door for new types of applications in power system protection and control. Intelligent Electronic Devices (IEDs) are equipped with various communication capabilities that make their functional integration a natural next step. Existing integration of substation equipment is not capable of clustering with the purpose of pooling hardware resources. <p> Presently, every electric device requiring protection has its dedicated hardware performing the predetermined set of protective functions. A new function-based protection and control philosophy is proposed, based on an open-system solution. In the proposed system, the resources of the protective and control hardware are pooled, and as a clustered system provide each protected unit (line, transformer, breaker, etc) with functions required for complete direct and backup protection. <p> The work presented in this thesis identifies the performance requirements of a digital relaying algorithm for processing samples that are sent across Ethernet-based communication channels. The work shows the shortcomings and unstable performance of widely used protective algorithms in accommodating data samples that are out of step from their proper position due to variable time delays of the communications media. A new digital relaying algorithm was developed that is able to extract the amplitude and phase angle of signals from data samples received across Ethernet networks with variable jitter. <p> The performance of the algorithm was tested by using the recovered phasor amplitude and phase angle information in protective solutions. The results show that there is significant flexibility in the algorithm that can be used to facilitate less performant communication channels, or, to take advantage of faster communications channels by reducing the response time of the protective function. <p> The results show that the algorithm works well with variable length data windows, and variable sampling frequencies. Higher sampling rates make communications problems more visible, but the presented algorithm is able to compensate for wide variations in network performance, effectively maintaining sampled signal phase and amplitude information during network performance fluctuations.

Thesis (M.S.)--West Virginia University, 2002. / Title from document title page. Document formatted into pages; contains ix, 129 p. : ill. (some col.). Includes abstract. Includes bibliographical references (p. 125-129).

The combination of traditional process migration and the new virtualization technology enables mobility of virtual machines and resource provisioning within data centers. While applied to wide area network (WAN), a traditional migration algorithm has to adjust itself according to the various WAN situations and VM status. This thesis identifies four performance measurements of a VM migration: total migration time, downtime, remote up time and performance degradation. It observes that the total migration time and the remote up time of traditional pre-copy over WAN is too long to tolerate. This thesis claims that even for WAN, post-copy could be used to improve the total migration time and remote up time, only by introducing tolerable, predictable and controllable performance degradation. The adaptiveness of the migration algorithm is concerned. It proposes a hybrid solution of pre-copy and post-copy, both for memory and storage, to do the migration. In the hybrid solution, a fraction of memory (Mfrac) and a fraction of storage (Sfrac) are migrated in the pre-copy and freeze-and-copy phase, and the remaining are migrated in the post-copy phase. A model-based solution with the help of profiling is proposed to adaptively find the best combination of Mfrac and Sfrac. The evaluation part suggests that the proposed solution could adapt to different application behaviors and network conditions. / published_or_final_version / Computer Science / Master / Master of Philosophy

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Thesis (Ph. D.)--University of Washington, 1994. / Vita. Includes bibliographical references (leaves [209]-216).