Reliability Evaluation of Small Isolated Power Systems

Abstract

Probabilistic methods have largely replaced deterministic techniques in the assessment of generating capacity adequacy in large modem electric power utilities. In spite of their widespread application in large systems, probabilistic methods are not generally applied to small isolated power systems. A recent survey [6] by Newfoundland & Labrador Hydro indicates that all Canadian small isolated systems employ some type of deterministic method to assess the adequacy of the existing or proposed generating facilities to meet the total load requirement. These approaches do not normally include any explicit recognition of system risk and do not provide comparable risks for systems of different size or composition. The reluctance by system planners of small isolated systems to accept probabilistic methods in their present form dictates a need to develop new approaches to bridge the deterministic methods and the prevalent probabilistic techniques. This thesis presents a new approach, known as system well-being analysis that links the accepted deterministic criteria with probabilistic methods. A description of the new evaluation techniques, new adequacy indices and comparative studies of the different indices and approaches are presented with the objective of providing practical probabilistic methods for capacity planning in small isolated power systems. A graphical user-interface software package named SIPSREL has been developed as a practical tool for small isolated system planning. It is hoped that probabilistic methods will be employed in practice in the adequacy evaluation of small isolated power systems using the methodologies and evaluation tools that have been developed in this research work.