A Fire-Risk-Breakdown System for Electrical Power Lines in the North of Brazil

Anthropogenic or spontaneous fires (hotspots) are the main causes of unexpected breakdowns of electrical power lines in the northern region of Brazil. This research has tested, adapted, and implemented a preoperational system aiming to prevent electrical breakdowns for 382 km of electrical transmission lines in the state of Maranhão. The breakdown electrical fire risk is based on a combination of three variables: 1) the fire risk index, 2) the remotely sensed hotspot presence in the vicinity of electrical power lines, and 3) the vegetation stage. These variables are converted into Boolean variables, and their combination will classify the electrical fire risk as extreme, high, medium, low, or null. In regard to the system input variables, the fire risk index carries the highest representativeness in composition value of the breakdown electrical fire risk. Therefore, the results of two fire risk indices, calculated on the basis of the (a) Monte Alegre and (b) Angstrom methods, are presented and discussed. The validation of the fire risk indices is based on six categorical statistics (with the obtained final values also indicated in parentheses for the Monte Alegre and Angstrom methods, respectively): accuracy (0.91, 0.92), bias (1.05, 1.06), probability of detection (0.98, 0.99), false-alarm ratio (0.07, 0.07), probability of false detection (0.90, 0.80), and threat score (0.91, 0.92). The system presented here may be used as a tool within the electrical sector to prevent and respond to sudden electrical power line breakdowns.