Radio Interference Performance of HVAC Conductor Bundles at High-Altitude Location: Measured Data Analysis and Altitude Correction

Abstract

Radio interference (RI) induced by the corona discharge of alternating current transmission lines is more severe at high altitudes than at low altitudes; hence, RI is a crucial limiting factor in the structural design of transmission lines and environmental impact assessments. To determine RI performance at high altitudes, the State Grid Corporation of China constructed an ultrahigh-voltage (UHV) corona cage in Xining in 2015 at an altitude of 2261 m. In this study, the cage was used to investigate a high number of bundled conductors under heavy rain. An RI excitation function was derived from Xining and the effects of several variables on RI performance were analyzed. In addition, RI altitude corrections were studied by comparing the Xining data with data obtained from a UHV corona cage in Wuhan located at an altitude of 23 m. The RI correction value was verified not to be a constant value but rather one that changed with the surface electric field and bundle size. The correction values obtained in this paper could enable the RI levels of high-voltage alternating current transmission lines at high altitudes to be evaluated more precisely.