The±800 kV converter station was attacked by typhoon and the conductor fracture fault was occurred at C

1

low voltage terminal of suspension capacitor tower of DC filter c apacitor bank

causing the DC filter to trip and out of service.In this paper

the fracture mechanism was analyzed by way of scanning electron microscope and chemical composition（ICP-OES） detection ect.The finite element model of capacitor tower was set up and the structural response of the capacitor under wind load was calculated.According to the simulation calculation results

the reason for fracture of conductor is that during the design period the displacement of the capacitor tower under wind load was not considered.The swing of

the capacitor tower under strong wind keeps the aluminumstrand stretched and extruded and causes fatigue damage and fracture due to long time It is suggested that the displacement of capacitor tower and the requirement of long-term operation should be fully taken into account so to improve the design margin of this conductor during the preliminary design for a new DC project.