Risk Assessment Model for Converter Transformers Based on Entropy-Weight Analytic Hierarchy Process

As a critical component in voltage–current conversion and power transmission within HVDC systems, the risk assessment of converter transformers plays a significant role in ensuring their operational safety and enhancing the reliability of the power supply. To address the issues of the incomplete characteristic parameters and limited fault data used for model training in existing transformer evaluation models, this paper develops a risk assessment model for converter transformers based on the entropy-weighted analytic hierarchy process (AHP). Firstly, in accordance with relevant standards in the power industry and existing experimental research, 14 ‘electrical–thermal–mechanical’ multi-dimensional characteristic parameters, including partial discharge, dissolved gases in oil, and hot spot temperature rise, are selected to effectively reflect the risk state of converter transformers. The risk state is then categorized into four levels. Next, the AHP, which uses a subjective weighting method, is combined with the entropy-weight method, an objective weighting approach, to construct the risk assessment model for converter transformers based on the entropy-weighted AHP. Finally, the effectiveness of the model is validated through four case studies of converter transformers. The results indicate that the risk assessment model proposed in this paper can accurately and effectively reflect the risk state of transformers at different levels, providing valuable guidance for the development of maintenance strategies for converter transformers.