To reduce the damage from the power frequency follow current of distribution lines, a multi-fracture compression airflow arc-extinguishing structure is studied. The structure is mainly composed of a compression tube, a metal electrode, and metal connection fittings, and the multi-fracture compression airflow arc-extinguishing body is formed by the combination of packaging and insulation fittings. The body and the air gap are parallel to both ends of the insulator. When lightning strikes, the internal short gap of the main body and the air gap break down, and the lightning arc enters the arc-extinguishing body through the breakdown channel. In the structure, the arc is compressed by force to form internal and external gradients of temperature and to produce jet airflow. The jet airflow acts on the subsequent power frequency follow current arc, which is suppressed and extinguished. In this paper, a model coupling an arc and a compressed jet airflow in a multi-fracture compression airflow arc-extinguishing structure is established theoretically and simulated by simulation software. Finally, a power frequency follow current interruption test is carried out. The simulation results show that a high-speed airflow of 600 m/s is formed around the fracture at approximately 0.99 ms, and the airflow is proportional to the rate of temperature variation. The test results show that the power frequency follow current of 1.289 kA is cut off within approximately 3 ms without a reburning phenomenon. The effect of power frequency follow current interruption is obvious in the structure.

A dual-jet arc-extinguishing method is proposed in order to improve the performance of jet-extinguishing gaps for extinguishing large currents and reducing the lightning trip-out rate of power lines. Meanwhile, we studied the arc-extinguishing effect of the dual-jet non-equilibrium field gas flow. Based on this, a Double Jet Arc Extinguishing Gap (DJAEG) is developed. First of all, the jet field arc extinction modeling analysis is carried out by coupling the typical MAYR arc model with the jet field. Then, the COMSOL MUTIPHSICS simulation software is used to simulate the arc extinction of the DJAEG in the balanced flow field and the non-balanced flow field. Finally, the DJAEG extinguishment arc test is carried out through the construction of the power frequency continuous flow interruption test. The simulation results show that the velocity of the high-speed jet emitted by the DJAEG can reach 3000 m/s, and the arc can be extinguished within 4 ms. These results also verified that the dual jet non-equilibrium flow field has the characteristics of long jet sustaining time. The test results show that the DJAEG successfully extinguished the arc within 4 ms, and there was no reignition. This means that the dual-jet non-equilibrium field has an obvious arc extinction effect.