Stability-constrained offshore transmission planning for large-scale remote wind farm

VSC-HVDC system is a recent technology, which has demonstrated its effective power system controllability. It cannot only facilitate long-distance bulk power transmission but also provide auxiliary services, including voltage regulation services to connected AC system. How to efficiently utilize its advantages and properly integrate multi-terminal HVDC into an existing AC system is a worthwhile issue. This paper deals with the issue of utilizing MTDC system to integrate multiple offshore wind farms into AC systems. A comprehensive decision support model is proposed which covers three key factors that characterize offshore wind farm integration: investment cost, system stability and the interactions between MTDC and local AC system. The main decisions concern integrated AC bus location and appropriate converter size installed at the corresponding MTDC terminals. To better fit into the real-world operation, various wind speed and load scenarios have been considered. The proposed model has been tested to integrate two wind farms to a benchmark AC system via a MTDC grid. The case study will be used to demonstrate how the proposed model can be used as a decision-making tool for grid connection of multiple wind farms via MTDC transmission technology.