Effect of Rain Intensity on Radio Interference of HVAC Conductor Bundles at High-Altitude Location

At high altitudes, the corona discharge of alternating current transmission lines is more severe, and the induced radio interference (RI) level is higher. Foul weather, especially rain, can aggravate RI performance. In this article, to investigate the influence of rain intensity on RI level at high altitudes, an ultra-high-voltage (UHV) corona cage was employed to perform RI measurements for four bundled conductors (4 × LGJ 630, 6 × LGJ 500, 8 × LGJ 500 and 8 × LGJ 630) by using an artificial rain system at an altitude of 2261 m. The RI levels of the four conductors were obtained under fair weather and under 1.5, 2, 6, 12, and 18 mm/h of rainfall. Then, the RI performances of a 1000 kV UHV single circuit lines and a 1000 kV double circuit line on the same tower were calculated using the excitation function approach. Finally, the difference between predicted RI values at high altitude and long-term measurements for operational power lines at low altitude were discussed.