Methods for Enhancing Reliability of Large Sending-End Systems in High-Penetration Renewable Energy Power Bases

The widespread adoption of High Voltage Direct Current (HVDC) transmission in large-scale renewable energy bases has intensified reliability challenges in power sending systems with high renewable energy integration. In this paper, we investigate the reliability enhancement methods for Large Sending-End Systems (LSES), proposing a subsystem-based reliability assessment and tracing model. Firstly, we analyze the renewable-HVDC integration architectures and divide systems into subsystems (wind turbines, photovoltaic systems, converter stations, and DC lines), applying two-state Markov models and state enumeration for reliability quantification. What’s more, we implement reliability tracing to identify critical vulnerabilities (e.g., DC transmission lines, valve groups) and quantify their impact on system failure probability and frequency. Case studies demonstrate that high renewable penetration reduces system availability, primarily due to converter transformers and DC lines showing elevated failure rates. Based on this analysis, we propose measures including redundant configurations, achieving subsystem availability improvement. This research provides both theoretical foundations and practical guidance for power system reliability design and operation under high renewable energy penetration scenarios.