Condition Assessment and Maintenance Strategy of Flexible DC Distribution Equipment Based on Improved FMEA

Flexible DC distribution technology is a key supporting technology for the flexible transformation of distribution networks. Several demonstration projects of flexible DC distribution networks have been put into operation domestically. However, the condition assessment methods and maintenance strategies for flexible DC distribution equipment are not yet established, leading to challenges such as complex maintenance operations, high workload, and low levels of precision. To address these issues, this paper proposes a condition assessment method for flexible DC distribution equipment based on improved Failure Mode and Effect Analysis (FMEA). First, the potential failure mechanisms and condition indicators of key components of flexible DC distribution equipment are analyzed, and critical state variables are identified. Evaluation criteria for failure degree, importance, and detection rate of these state variables are then developed to achieve quantitative condition assessment of the equipment. Based on the assessment results, differentiated maintenance and operation strategies are formulated. Finally, the method is validated through an analysis of a converter as an example. This approach is also applicable to other flexible DC distribution equipment and can enhance maintenance efficiency and precision.