Due to the on-going worldwide trend towards investment in de-regulated electricity markets driven by political, economic and environmental issues, increasing interconnection between modern power systems has made power system dynamic studies much more complex. The continuous load growth without a corresponding increase in transmission network capacities has stressed power systems further and forced them to operate closer to their stability limits. Large power transfers between utilities across the interconnections stress these interconnections. As a result, stability of such power systems becomes a serious issue as operational security and reliability standards can be violated. On the other hand, the evolving technology of Wide-Area Measurement Systems (WAMS) has led to advanced applications in Wide-Area Monitoring, Protection and Control (WAMPAC) systems, which offer a cost-effective solutions to tackle these challenging issues.The main focus of this research project was to develop a wide-area based stability enhancement control scheme for large interconnected power systems. A new method to identify coherent clusters of synchronous generators involved in wide area system oscillations was the initial part of the work. The coherent clusters identification method was developed to utilise measurements of generators speed deviation signals combined with measurements of generators active power outputs to extract coherency property between system's generators. The obtained coherency property was then used by an agglomerative clustering algorithm to group system's generators into coherent clusters. The identification of coherent clusters was then taken as a base to propose a new structure of a WAMS based stability control scheme. The concept of WAMS and a nonlinear control design approach (fuzzy logic theory) was used to provide a comprehensive new control algorithm. The objectives of the developed control scheme were to enhance and improve the control performance of modern power systems. Thus, allowing improved dynamic performance under severe operation conditions. These objectives were achieved by means of enhanced damping of power system oscillations, enhanced system stability and improved transfer capabilities of the power system allowing the stability limit to be approached without threatening the system security and reliability.
|Date of Award||31 Dec 2013|
|Supervisor||Roderick Dunn (Supervisor)|