Facilitating the Validation of Adaptive Power System Protection through Formal Scheme Modelling and Performance Verification

摘要

There exists a critical mass in research related to adaptive protection approaches that address some of the shortcomings of conventional protection functions. This is in response to concerns in the reliability of conventional protection which manifested itself in some severe disturbances in more recent years. Despite the fact that adaptive protection offers a compelling technical solution to some of these performance problems, the industry has not widely adopted adaptive protection approaches as a de facto policy for future protection scheme implementations. This is attributed to the difficulties associated with the testing of such schemes where no significant work has been reported yet. Furthermore, the benefits vs. the risks associated with such a protection strategy are not well understood. This is coupled with the conservatism towards radical changes in the way the power system is operated. As such the work reported in this thesis complements the existing body of research in order to address some of the major technical and institutional challenges associated with adopting adaptive protection schemes for future networks, especially those networks that exhibit flexibility in operation to deal with uncertainty in generation and to maximise asset utilisation. These are network characteristics that adaptive protection approaches are seen to be an effective enabler of. This thesis focuses on formal structural and behavioural modelling of adaptive protection schemes as means to effectively validate their functional operation and verify their performance. Novel contributions have been made in formalising a user requirements driven architecture for these schemes. Furthermore, significant contributions have been made to conducting formal algorithm verification that complements inherently limited standard protection scheme validation techniques. The thesis makes thorough use of a proposed adaptive distance protection scheme for circuits with quadrature booster transformers to communicate the challenges, lessons learned and contributions in designing, implementing and testing adaptive protection schemes.