Online and Offline Stability Assessment Development at National Grid, UK

Developments of the National Grid Online and Offline Stability Assessment (OSA/OFSA) systems are presented here. Business requirements are outlined, technical implementations summarised, and examples of use cases given. OSA is capable of identification of unknown system stability issues during real-time operation; while OFSA provides what-if assessment in the operational planning phase. Performance of OSA meets the requirement for analysing the full contingency set (more than 2000 cases) in each State Estimation cycle. Consistency between OSA and OFSA has been addressed. OSA and OFSA together support National Grid’s delivery of the GB Security and Quality of Supply Standards in a changing and more uncertain environment.