Risk assessment method for external breakage of overhead lines in mining areas

The operating environment of overhead lines in mining areas is harsh. The lines are easily affected by external factors, leading to line breakage. It is necessary to accurately evaluate the risk level of external breakage of overhead lines in mining areas. However, existing qualitative evaluation methods have shortcomings such as strong subjectivity and poor comparability of evaluation results. Although quantitative evaluation methods have high objectivity, the accurate evaluation is based on a large amount of high-quality data. In order to balance the objectivity of the evaluation results and the difficulty of obtaining evaluation data, the likelihood exposure consequence (LEC) method in semi quantitative evaluation method is adopted. Based on the actual operating environment of mining area lines, an improved LEC method is proposed for the risk assessment of external breakage of overhead lines in mining areas. Firstly, by analyzing the actual operating environment of overhead lines in mining areas, the main risk factors of external breakage are identified. The risk assessment index system for external breakage of overhead lines in mining areas is constructed. Secondly, using the YOLOv5 based image recognition strategy to identify the sources of external breakage risk in the line environment, real-time acquisition of external breakage risk data of the line is achieved. It overcomes the shortcomings of poor real-time performance and insufficient data volume obtained manually by traditional LEC methods. Thirdly, the element assignment rules of the LEC method are improved. The elements are assigned based on image recognition results to achieve real-time evaluation of the risk of external breakage to the line. It improves the objectivity of the evaluation results and solves the problem of the traditional LEC method's element assignment relying on the personal experience of the evaluator. Finally, in order to measure the superimposed impact of various risks, the analytic hierarchy process is used to determine the weight of each risk evaluation index. Ultimately, the comprehensive assessment of the risk of external breakage to overhead lines in mining areas is achieved. A case study is conducted during the actual operation of an open-pit coal mine. The results show that this method can effectively evaluate the risk level of external breakage of overhead lines in specific scenarios.