Equivalence of DC Corona Loss Based on Small Corona Cages and Simplified Test Lines

The direct current (DC) corona loss data obtained by using corona cages and test lines cannot be directly applied to actual DC transmission lines. In order to explore the equivalence of corona loss of conductors with different geometric structures, a test platform for DC corona discharge was built. In addition, the change law of corona loss of conductors with different geometric structures was investigated. The experimental results showed that the corona loss decreases with the increase of the radius of corona cages and the height of test lines above the ground. A generation function of corona loss containing only geometric parameters was defined. Based on the function, the equivalence of test data was studied and a method was obtained to translate the measurement data on the corona loss under one geometric structure to a variety of geometric structures.