Study on the Decrease in Air Dielectric Strength of DC Voltage According to the Ignition Properties of Combustibles

Most electrical transmission lines are located in forests, and currently in South Korea, deregulation has allowed various structures to be built on the ground below transmission lines. Events of fires occurring below high-voltage transmission lines can lead to large-scale electrical accidents. To prevent such accidents, this study examined the ignition properties of combustible materials and their relationship with the reduction in air dielectric strength. Experiments were performed on two types of synthetic resins and lumbers, namely cypress and pine. A cone calorimeter was used to measure ignition properties such as effective heat of combustion, heat release rate, and soot yield. In addition, we built a dielectric strength testing device to measure the reduction in air dielectric strength caused by flames. These measurement results can serve as a basis for revising fire safety standards