On Corona Testing of High-Voltage Hardware Using Laboratory Testing and/or Simulation

Hardware designed for use on high-voltage transmission lines must be designed to be free of corona. Historically, design adequacy has been verified by testing in the laboratory. However, this is problematic because laboratory testing is done using a single-phase system and the electric fields on the surface of the hardware (the driver of corona) are different between laboratory and field environments. Using three-dimensional simulations, it is shown that this difference is significant. Hence, the use of single voltage testing is problematic. In addition, the use of a corona sphere to match laboratory conductor electric fields to those in the field does not improve the process. Furthermore, it appears feasible to replace (at least some) testing with simulation.