Reliability evaluation of voltage-source converter-based multi-terminal direct current integrated offshore wind plants

A novel analytical approach to reliability evaluation of voltage-source converter-based multi-terminal direct current (VSC-MTDC) integrated offshore wind plants is presented in this study. To treat the multi-terminal grid precisely and efficiently, the approach combines the state evaluation method and network flow method. A DC line equivalent component is also proposed to consider the operation modes, failure clean measures as well as interactions between different DC lines of VSC-MTDC. Employing this approach, the authors can obtain both frequency and probability indexes of reliability. The usefulness and effectiveness of the proposed method are verified by case studies. The comparison between three popular schemes is also carried out.