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 µm, 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.

Batteries with an energy storage capacity of 280 Ah play a crucial role in promoting the development of smart grids. However, the inhomogeneity of their internal temperature cannot be accurately measured at different constant charge and discharge power, affecting the efficiency and safety of the battery. This work adopts finite element analysis to determine the typical internal temperature of a single-cell model, which can guide the measuring position of the battery. Before the manufacturing process, a slim pre-buried sensor is utilized to reduce the negative impacts of different constant charge and discharge powers. The maximum internal temperature of the battery is up to 77 °C at a constant charge and discharge power of 896 W. The temperature difference between the two poles and the battery surface is as high as 26.2 °C, which is beyond the safety temperature (55 °C). This phenomenon will result in the degradation of the positive electrode through dQ/dV curves. These measurements of battery internal temperature can improve battery heat control and facilitate the development of energy storage technology.