Recovery Time Representation Based on Post Arc Plasma Dissipation Using a Vertical Extension Arcing Horn

A suitable reclosing time is important to guarantee the reliability of the power supply after a temporary failure in dc transmission lines. The design of the reclosing time mainly depends on the recovery time of the insulation strength. Here, an experimental platform was built that can simulate a real situation using a vertical extension arcing horn based on the post arc plasma dissipation. The entire macroperformance process, voltage and after-current characteristics were analyzed. The recovery times were measured under the conditions of the output current from 10 to 200 A and an initial gap length from 1 to 80 mm. The results show that the after-current can better represent the recovery time. The recovery time is a double-exponential function of the gap length and a power function of the initial current. The longest recovery time is 210 ms when the current is 200 A and the initial gap length is 1 mm, while the shortest recovery time is only 60 ms when the current is 10 A at an initial gap length of 40 mm. The entire process of the macroperformance contains three periods: the arc fuse burst, the transient arc extinction, and the post arc plasma dissipation. The maximum gap length for generating a continuous dc arc via the arc fuse is 0.4 mm when the terminal voltage is 560 V and the minimum current for this dc arc's maintenance is 3.5 A under the condition of the maximum gap length. This article is aiming to provide some references for the reset of the reclosing times used in dc transmission grounding lines.