Arc Characteristics of Transverse Magnetic Electrode with Different Central Platform

In the Jiangsu-Baihetan ultra high voltage (UHV) DC transmission project, the excess energy caused by overvoltage on the 400kV bus will threaten the electrical equipment. Therefore, it is necessary to install an energy dissipation device on the busbar, so that the energy of the fault overvoltage can flow into the ground quickly and reliably. The trigger switch is applied in this energy dissipation device. The main electrode of the switch adopts a spiral groove structure, and the arc rotates around the edge of the electrode at high speed under the Lorentz force, which reduces the ablation of the electrode by the large current and improves the service life of the trigger switch. The magneto hydro dynamic (MHD) arc model is applied to simulate the arc movement characteristics. The influence of the main electrode’s diameter of central platform area in the trigger gap switch is investigated. And the arc control ability of electrode is analyzed.