①External insulation problem. With the deteriorating operating environment, porcelain post insulators have insufficient anti-pollution flashover capability. For UHV DC, pure ceramic post insulators require a large creepage distance and structure, while too high post insulators are difficult to achieve strong bending and seismic strength.
②Anti-earthquake problem. The high-voltage equipment that uses the electric porcelain pillar insulator as the insulating component is simply referred to as the electric-porcelain type high-voltage equipment. The earthquake resistance of such equipment has been difficult to solve well. In the 2008 Wenchuan Earthquake, most of the damage to high-voltage equipment was due to broken ceramic bushings. For the UHV DC system, the pillar insulator used for smoothing reactors requires an overall height of 12m and a supporting mass of 40t, and the converter station is located in Chuxiong, Yunnan, where earthquake-prone areas are located. Obviously, it is very difficult for porcelain pillar insulators to meet the seismic requirements of.
③ manufacturing quality problems. Porcelain pillar insulators are difficult to manufacture due to their own complex process, equipment conditions, raw material quality problems and other limitations. Based on a large number of investigations, the working group of the high-voltage pillar porcelain insulator accident investigation team of the former State Power Company's Power Transmission and Operation Department counted the accidents of porcelain pillar insulators according to technical reasons, and concluded that the pillar porcelain insulators broke, and the product quality accounted for most of the conclusions. .