Study on Wind-Induced Vibration of Tension String Shielding Ring for UHVDC Transmission Lines Based on Modal Test

Under the action of natural wind, the shielding ring of tension string of UHVDC transmission line is prone to low frequency vibration, and the long-term vibration may lead to the fatigue damage of the shielding ring, threatening the safe operation of the line. In this paper, the modal test of the shielding ring of the tension string of UHVDC transmission line is carried out by using hammering method, and the natural frequencies and vibration mode shapes of the shielding ring are mastered. Combined with the analysis of the wind speed and wind direction in the engineering site, it is shown that the vortex induced vibration of the shielding ring is caused by the low-speed continuous stable wind along the line.