In view of such situation that the electrode layout is vertical to the two-phase flow of the wind and sand and the corresponding layout of electrode of the external insulation of actual transmission line in the sand dust weather is in the same direction in case of studying the discharge feature of typical air gap at sand dust environment by the scholars both at home and abroad

the study of the discharge at the layout of such electrode by the scholars both at home and abroad is rare. In this paper

the power-frequency breakdown characteristics of the rod-rod short air gap under the same direction and vertical direction of wind-sand two-phase flow is studied on the basis of sand environment simulation system. The test and study for such three conditions as neither wind or sand

wind without sand and both sand and wind is performed respectively in the range rod-rod short air gap at 0～20 cm. It is shown by the study that in case of vertical layout of two-phase flow of wind and sand with the electrode

the influence of the wind sand condition on the breakdown voltage is related to the distance. While

in case of same direction of the twophase flow of the sand and the wind with that of electrode layout

the wind-sand environment can reduce significantly the breakdown voltage within the gap distance of the test. In case of large gap distance

the breakdown voltage is lower when the wind-sand and the gap are arranged in the same direction. Therefore

the influence of layout of electrode on the typical air gap breakdown characteristic shall be considered in case of performing the design of external insulation of transmission line in the dust area. The study result in this paper is not only limited to the power-frequency discharge characteristics of rod-rod short air gap at dust conditions

but also provides a new method for studying the discharge characteristics of long air gap at dust condition

that is to consider the way electrode layout

and guides reasonably the external insulation design of the transmission line in the dust area.