It is necessary to study the effects of wind speed and dust particle size on DC corona inception voltage of fittings so as to design and maintain HVDC transmission lines under extreme climate conditions. Therefore

four different-sized aluminum grading rings were taken as research objects. The corona inception voltage of each of these grading rings was tested under three experimental conditions: still air

10

2

5 m/s wind speed with dust particles

and the diameter of particle is under 65 μm and 105 μm

respectively. The results were then verified by ANSYS simulation. It is indicated that the corona inception voltage will decreases under the influences of wind and dust particles. Moreover

the voltage under the same dust-particle concentration increases along with the wind speed raising. The voltage under 65-μm diameter dust particle

s is lower than that under 105-μm ones at each wind speed.