Study of Corona Loss Characteristics of 750 kV AC Bundle Conductors Under High‐Altitude Location of 4300 M

ABSTRACT Corona loss is an important technical factor for the construction of ultra‐high voltage (UHV) and extra‐high voltage (EHV) AC transmission lines. In high‐altitude areas, the atmospheric pressure decreases and the ultraviolet rays increase, making it easier for the corona onset of conductors. The control of corona losses is even more essential. Currently, there is little research on the corona loss level of multiple bundle conductors for 750 kV EHV AC projects in high‐altitude conditions above 4000 m. In the paper, based on the large corona cage in Yangbajing, Tibet, China, at an altitude of 4300 m, the corona losses of the 6 × LGJ500, 6 × LGJ630 and 8 × LGJ500 conductors were measured by the corona loss measurement system under conditions of dryness, heavy rain and wet conductors. By taking typical 750 kV EHV‐AC single‐circuit and double‐circuit transmission lines as an example, the corona loss equivalent method was used to evaluate the corona loss of transmission line conductors at high altitudes.