A Correction Formula Considering Sand and Dust for Corona Loss of Bundle Conductors in an EHV AC Corona Cage

Abstract

Corona cages are the main tool to study corona characteristics of alternating-current (AC) and direct-current (DC) transmission lines. Through use of a corona cage and a sand and dust environment simulation system, corona characteristics of lines in sand and dust weather can be well obtained. However, the simulation system increases the test cost and limits the test conditions. In order to get the influence of sand parameters on the corona loss of bundle conductors, AC corona discharge tests were carried out on bundle conductors by using an extra-high voltage (EHV) AC corona cage under different sand parameters, and the change law of corona loss with sand parameters was obtained. According to the test results, a correction formula considering sand and dust for the corona loss of bundle conductors is put forward, which is suitable for the sand particle size of 0–0.5 mm and the sand concentration of 220–460 mg/mm3 at the altitude of 2,200 m. Through this formula, the corona loss under conditions of known sand parameters can be calculated based on measured corona loss under conditions without sand or dust, which saves the test cost and provides reference for engineering design.