Purpose This paper aims to evaluate and compare the reliability of four far-sea offshore wind power lightweight transmission schemes, namely, Low-Frequency Alternating Current, Uncontrolled Rectification, Parallel Hybrid Rectification and Series Hybrid Rectification, for offshore wind power systems to support engineering scheme selection and redundancy design. Design/methodology/approach The Reliability Block Diagram method, combined with hierarchical modeling, is used to assess system reliability from component to system level. The analysis also considers different redundancy strategies and redundancy ratios. A case study based on an actual offshore wind project is presented. Findings The results of this study show that Low-Frequency Alternating Current demonstrates superior reliability during short-term operation, while Uncontrolled Rectification outperforms other schemes in long-term operation. Hybrid rectification schemes (Parallel Hybrid Rectification and Series Hybrid Rectification) achieve an optimal balance between cost and reliability. Furthermore, the adoption of cold backup strategies and an increased redundancy ratio (5%–10%) further enhance system reliability. The findings of this study address the gap in quantitative reliability assessments for mid- and far-offshore transmission systems. Originality/value This paper provides a systematic and quantitative reliability assessment framework for lightweight offshore wind power transmission systems. By integrating Reliability Block Diagram-based analysis with component-level modeling, this study offers practical guidance for engineering scheme selection and redundancy optimization, supporting the development of reliable and cost-effective marine energy infrastructure.
Wang et al. (2026) studied this question.