IHGR-RAG: An Enhanced Retrieval-Augmented Generation Framework for Accurate and Interpretable Power Equipment Condition Assessment

Condition assessment of power equipment is crucial for optimizing maintenance strategies. However, knowledge-driven approaches rely heavily on manual alignment between equipment failure characteristics and guideline information, while data-driven methods predominantly depend on on-site experiments to detect abnormal conditions. Both face challenges in terms of inefficiency and timeliness limitations. With the growing integration of information systems, a significant portion of condition assessment-related information is represented in textual formats, such as system alerts and experimental records. Although Large Language Models (LLMs) and Retrieval-Augmented Generation (RAG) show promise in processing such text-based information, their practical application is constrained by LLMs’ hallucinations and RAG’s coarse-grained retrieval mechanisms, which struggle with semantically similar but contextually distinct guideline items. To address these issues, this paper proposes an enhanced RAG framework that integrates hierarchical and global retrieval mechanisms (IHGR-RAG). The framework comprehensively incorporates three optimization strategies: a query rewriting mechanism based on few-shot learning prompt engineering, an integrated approach combining hierarchical and global retrieval mechanisms, and a zero-shot chain-of-thought generation optimization pipeline. Additionally, a Task-Specific Quantitative Evaluation Benchmark is developed to rigorously evaluate model performance. Experimental results indicate that IHGR-RAG achieves accuracy improvements of 4.14% and 5.12% in the task of matching the solely correct guideline item, compared to conventional RAG and standalone hierarchical methods, respectively. Ablation studies confirm the effectiveness of each module. This work advances dynamic health monitoring for power equipment by balancing interpretability, accuracy, and domain adaptability, providing a cost-effective optimization pathway for scenarios with limited annotated data.