The aim of this proposal is to appoint an additional professor in the field of electrical energy and power systems at The University of Manchester. Since candidates for this position cannot hold a permanent academic position in the UK, his/her appointment will increase the pool of experienced researchers working in a field that has been recognised as being not only critical to the health of the UK economy and quality of life but also below the critical mass required for a sector undergoing a major transition.

Following a series of serious power blackout incidents in 2003, policy makers in the European Union and the USA have highlighted (i) the need for improved a.c. transmission grid infrastructure and advanced control technologies to enhance stability and security in an increasingly complex operating environment, and (ii) the importance of emerging measurement-based technology towards achieving such enhanced operation. The concept of this proposal is a system for transmission security assessment using the emerging measurement technologies of high-bandwidth SCADA systems and the wide area measurement systems (WAMS) which are based on time-synchronized phasor measurement units. It will lead to better situational awareness and initiate control action for optimal operation closer to loading constraints while reducing the risks of blackouts.Very recent developments in measurement-based analyses being used in oil, gas and chemicals plants point the way towards much better signal analysis applications for the emerging measurement-based technologies in power transmission systems. The measurement-based system proposed in this project would greatly extend the basic methods that are used at present and will lead to localization and real-time diagnosis of the root causes of threats to transmission system security and actions to control the situation. It offers a more predictive, responsive and accurate approach than the transmission system models which are currently used, while the signal analysis methods now being used in experimental WAMS and high-bandwidth SCADA systems would advance from their current narrow emphasis on Fourier methods adopted from the aerospace industries. For instance the project would develop signal analysis methods for use when transient events excite system non-linearities. This will provide a much more accurate indication of the true situation during developing emergencies.This project is timely and is giving an immediate response to research needs identified in the Spring of 2006 in policy documents from the EU and US. Success in shifting the emphasis from model-based to measurement-based assessments will benefit the wider field of a.c. transmission stability and security as well as creating an a.c. transmission security enhancement system in a fit state for technology transfer. A first-rate team has been assembled for the task, namely Imperial College London (expertise in robust damping control of inter-area oscillations) and UCL (expertise in measurement-based analysis for process systems), National Grid (provision of high-bandwidth SCADA data, system specification and testing, a UK industrial viewpoint) and ABB (provision of PMU data, system development, the industrial viewpoint from continental Europe). The university researchers will do part of the work on secondment with National Grid and ABB. It is quite realistic to expect success from this team.

Following a series of serious power blackout incidents in 2003, policy makers in the European Union and the USA have highlighted (i) the need for improved a.c. transmission grid infrastructure and advanced control technologies to enhance stability and security in an increasingly complex operating environment, and (ii) the importance of emerging measurement-based technology towards achieving such enhanced operation. The concept of this proposal is a system for transmission security assessment using the emerging measurement technologies of high-bandwidth SCADA systems and the wide area measurement systems (WAMS) which are based on time-synchronized phasor measurement units. It will lead to better situational awareness and initiate control action for optimal operation closer to loading constraints while reducing the risks of blackouts.Very recent developments in measurement-based analyses being used in oil, gas and chemicals plants point the way towards much better signal analysis applications for the emerging measurement-based technologies in power transmission systems. The measurement-based system proposed in this project would greatly extend the basic methods that are used at present and will lead to localization and real-time diagnosis of the root causes of threats to transmission system security and actions to control the situation. It offers a more predictive, responsive and accurate approach than the transmission system models which are currently used, while the signal analysis methods now being used in experimental WAMS and high-bandwidth SCADA systems would advance from their current narrow emphasis on Fourier methods adopted from the aerospace industries. For instance the project would develop signal analysis methods for use when transient events excite system non-linearities. This will provide a much more accurate indication of the true situation during developing emergencies.This project is timely and is giving an immediate response to research needs identified in the Spring of 2006 in policy documents from the EU and US. Success in shifting the emphasis from model-based to measurement-based assessments will benefit the wider field of a.c. transmission stability and security as well as creating an a.c. transmission security enhancement system in a fit state for technology transfer. A first-rate team has been assembled for the task, namely Imperial College London (expertise in robust damping control of inter-area oscillations) and UCL (expertise in measurement-based analysis for process systems), National Grid (provision of high-bandwidth SCADA data, system specification and testing, a UK industrial viewpoint) and ABB (provision of PMU data, system development, the industrial viewpoint from continental Europe). The university researchers will do part of the work on secondment with National Grid and ABB. It is quite realistic to expect success from this team.

Power transformers are designed to withstand the mechanical forces arising from various in-service events, such as over-voltage and lightning, which may cause deformation or displacement of winding. Among various techniques applied to power transformer fault diagnosis, frequency response analysis (FRA) can give an indication of winding deformation faults without expensive and interruptive operations of opening a transformer tank, which can minimise the impact on system operation and loss of supply to customers and consequently save millions of pounds in timely maintenance. However, in industrial practice, FRA is always used as a comparative method, by comparing a test frequency response with a reference set, which cannot provide an insight understanding of transformer internal faults. A range of research activities have been undertaken to utilise FRA in the development winding models but with limitations, such as too complicated models, large computation time and inaccurate responses in the high frequency range between 1MHz and 10MHz. The proposed research is to build on the experience already gained at Liverpool and to develop an accurate winding model and a reliable fault diagnosis approach. A new hybrid winding model will be developed by modifying the analytical approach and results of transformer winding analysis obtained by Rudenberg for each disc, and subsequently connecting the travelling wave equation of each disc in a form of Multi-conductor Transmission Line (MTL) model. This can significantly reduce the order of the model yet with good modelling accuracy in the high frequency range, which allows access to the current and voltage at any desired turns of a winding. The electrical parameters of the hybrid model will be estimated with the finite element method (FEM), and further identified with evolutionary algorithms based on actual FRA measurements. The characteristic signatures between particular winding faults and winding parameters will be derived, which can be employed to detect and distinguish winding deformation faults. Then, the simulation of the hybrid model will be used to extract high frequency fault fingerprints of FRA for improving the detection of small winding changes, which will be further examined and verified through laboratory studies. For typical winding fault diagnosis, both the quantitative and qualitative judgements are generally considered, which can be treated as evidence and are often incomplete and imprecise. The Evidential Reasoning (ER) algorithm is very suitable for combining such evidence with a firm mathematical foundation. In this project, an evidence-based fault diagnosis system will be constructed to aggregate diagnosis information and deal with uncertainties for reliable winding fault diagnosis. The work is to be carried out as a collaborative project between the University of Liverpool, OMICRON and NG, bringing together academic and industrial expertise in the field of transformer test, modelling and fault diagnosis. The outcome of the proposed research will be the new hybrid winding model and the evidence-based winding fault diagnosis system. The new approach aims to improve the fundamental understanding of multi-frequency signal propagation across a winding, which will allow extracting fault fingerprints in both the low and high frequency ranges and provide new diagnostic rules for early fault detection and location. The extracted high frequency fault fingerprints will provide a feasible solution for early fault detection, which can assist a FRA test kit manufacturer, e.g. OMICRON, in fully understanding FRA and improving test kit precision. The developed evidence-based system for winding fault diagnosis can be a useful decision support tool for utility companies, e.g. NG, for reliable fault diagnosis yet with high efficiency, when processing numerous FRA records.

With increasing opposition to building new transmission lines, transfer of bulk energy is going to be a major challenge in the UK and in many parts of Europe. Examples include the transmission link from the north of the UK to the load centres in the south and the corridor importing hydro power from north of Norway to the load centres near Oslo. It is therefore, absolutely critical that the existing power transmission assets are fully utilised by loading them much closer to their capacity. To ensure secure operation under such heavy loading, the dynamic performance of the system needs to be improved through appropriate control of voltage and power flow using the flexible ac transmission systems (FACTS) devices. It is often difficult to obtain accurate information about all the components (e.g. loads) of a power system which poses fundamental limitation on conventional model based control design. In the above context, this project aims at designing and validating a self-tuning control scheme for FACTS devices that rely solely on the measured signals and thereby, obviate the need for accurate system information. Such controllers are designed independent of the system operating condition and therefore, need no retuning with changes in system configuration. Use of more than one feedback signals from strategic locations, available though wide-area measurement systems (WAMS), can potentially improve the effectiveness of the FACTS controller. Hence, the control design needs to be formulated in a multi-variable framework. The performance of the controller would be validated in real-time through hardware-in-loop (HIL) simulation employing a test bench, emulating the behaviour of large power systems, and a commercial control simulator. The proposed project essentially integrates FACTS with WAMS and could potentially provide the developers and user of both these technologies a new edge.