LAUSR

SF₆/N₂ gas mixture can not only reduce the consumption of SF₆ in power system, but also effectively alleviate SF₆ greenhouse effect. Since SF₆/N₂ can decompose under the alternating current partial discharge(PD), its decomposition characteristics are closely related to PD attributes. Therefore, the fault diagnosis method can be established through its PD decomposition characteristics. However, at present, the decomposition characteristics of SF₆/N₂ mixed gas under PD have not been fully grasped, and the correlation characteristics between decomposition characteristics and PD intensity have not been obtained. To this end, this article uses pin-plate electrodes to simulate the typical metal protrusion insulation defects in GIS equipment. SF₆/N₂ decomposition experiments are conducted at different PD intensity to study the correlation between the PD decomposition characteristics of SF₆/N₂ mixed gas and PD intensity. The results show that: the generation rate of characteristic decomposition components such as SOF₂, SO₂, SO₂F₂, SOF₄, CF₄, CO₂, NO, NO₂, and NF₃ are positively correlated with PD intensity; NO₂ and (SO₂F₂+SOF₂+SOF₄+SO₂) can be used as the characteristic quantity to judge the whole process of PD, SO₂F₂ can be used as the feature to judge the early PD, and SOF₂ and SOF₄ can be used as the features to judge the severe PD. The results of this article will lay the foundation for the monitoring of equipment insulation status using SF₆/N₂ decomposition characteristics in the future.