Comparison of Positive Leader Propagation in Rod–Plane and Inverted Rod–Plane Gaps

In order to investigate the different features of the positive leader propagation in the rod-plane and inverted rod-plane gaps, the discharge experiments in a 3-m rod-plane gap and a 3-m inverted rod-plane gap were carried out under switching impulse voltage. The positive leader propagation process was recorded by using a high-speed CCD camera. Some aspects to describe the positive leader propagation characteristics of the rod-plane and inverted rod-plane gaps are obtained and compared in this paper, including the critical corona radius, the average continuous leader inception voltage, the axial leader velocity, and the final jump length. The possible reason resulting in those differences is also discussed here.