A Study on Probabilistic Reliability of HVDC Expansion Planning in South Korea

Abstract

This paper describes an alternative model, methodology, and case study for probabilistic reliability-based planning for High-Voltage Direct-Current (HVDC) grid expansion in a power system that includes wind turbine generators (WTGs). Ensuring the reliability of such a power system requires multi-state simulation because of the intermittent characteristics of wind speed. The power system includes an AC/DC converter and DC/AC inverter substation. The substation is composed of many thyristor devices, which can potentially fail. This problem was formulated as a hierarchical level II (HLII) reliability evaluation because HVDC transmission lines are considered. Using the proposed method, new HVDC contact bus points with the best reliability level can be chosen. The methodology was applied to a small-scale model power system.