Electrical safety of suppressing wildfires near high-voltage transmission lines using water mist

Abstract

Wildfires near transmission lines are important disasters that affect power transmission. Water mist is a highly efficient method for suppressing wildfires near electrical transmission lines, where it avoids line-tripping to ensure the safety of the grid. However, few studies have investigated the electrical safety during the water mist extinguishing process, including the risk of tripping transmission lines and the shock hazard for users. In this study, we systematically studied the influence of the gap distance and the electric conductivity of the water solution on the insulation characteristics of water mist with a Dv 0.99 diameter of the droplets of ca. 500 mm, including the breakdown voltage and leakage current. Furthermore, we investigated the effect of water mist on the development of a long-gap discharge, and the insulation mechanism of water mist was also considered. Finally, water mist with multi-component additives was employed for suppressing wildfires near transmission lines in China, and we demonstrated the effectiveness of this method based on the reduction of line-tripping accidents caused by wildfires near transmission lines.

Water Mist Fire Suppression Systems for Building and Industrial Applications: Issues and Challenges

“…There have been concerns regarding the use of water mist suppression as a replacement for halon and CO 2 because of the electrical conductivity of the water causing damage or creating a risk of shock to personnel. Through various studies, water mist has since been proven to be a feasible protection method for electrical equipment in computer rooms, datacentres, and electrical switch gear cabinets [35][36][37]. Fires within these environments are typically slow-growing, where burning plastic-coated cables and circuit boards spread corrosive smoke.…”

Power System Wildfire Risks and Potential Solutions: A Literature Review & Proposed Metric

“…First responders receive varying levels of training related to fire suppression near power lines and learn how to identify high voltage lines, but there is no standardized national protocol for this training (Pruitt and Panossian 2021). Traditional water sprayed from a hose can cause faults from lines to ladders, fire trucks, or even firefighters, creating the risk of a severe shock to responders and their equipment (Lu et al 2018). This risk is also present when there are responders on the ground and water is released onto the area from an aircraft (Lu et al 2018).…”

Fault Statistics and Analysis of 220-kV and Above Transmission Lines in a Southern Coastal Provincial Power Grid of China

“…And the number of trees under the corridors should be reduced. It is necessarry to strengthen the close contact with forestry and forest fire control departments, establish a fire linkage notification system, improve the isolation safety measures, do contingency measures for emergencies [18]. There are some application to prevent wildfire in transmission lines including intelligent monitoring and fire location system.…”