Small Corona Cage for Wideband HVac Radio Noise Studies: Rationale and Critical Design

Corona cages are used in overhead power line studies to investigate physical mechanisms involved in corona discharge and to predict radio noise generation. In this paper, we design a small laboratory corona cage to investigate wideband radio noise generation on practical HVac conductor bundles. We introduce and describe cage design criteria including the insulation of the cage mesh. Our measurement method generates data that can be used to calculate the characteristics of both fair-weather and foul-weather radio noise for interference studies over a wide bandwidth. We achieve this through time-domain measurements obtained on an 8-bit, 100-MHz sampling card. Single and multiple corona pulses are studied and we propose a single corona pulse source excitation function for small cages.