Effect of HVDC component enhancement on the overall system reliability performance

This paper examines several HVDC transmission system component enhancement schemes as they affect the overall system availability using a system model based on a practical system and actual system outage data. A frequency and duration approach is used in modeling the system components such as valve-groups, converter transformers, smoothing reactors, pole, and bipole controls, transmission lines, and the overall system model developed. This model is used to compare the impact on the overall system availability of different methods of HVDC converter enhancement. These methods include the addition of spare converter transformers, spare smoothing reactors, replacement of valves, and increase of converter rating. Finally the costs of typical enhancements are compared with the benefits arising with the improved availability using a cost-benefit analysis