High-Voltage Corona in Air

In the last few years contributions to corona literature by Holm, Ryan, Willis, and others have shown that the space charge liberated by alternating corona reacts on the corona to a high degree in determining its characteristics. This investigation studies the nature of these effects as influenced by variation in the limits of travel of the space charge. The three properties of corona readily lending themselves to experimental observation, the wave form and the value of the corona current, and the corona loss, have been observed when high alternating voltages are applied to a small smooth cylindrical conductor placed successively along the axes of four sizes of metal cylinders. In addition four frequencies of the alternating voltages were used. All the work has been done under atmospheric conditions. The theory of the influence of space charge as developed by Holm has been tested by experiment and a marked discrepancy is indicated. Values of power loss due to corona, as measured, differ appreciably from those predicted by Holm, but in general follow the quadratic relation suggested by Peek. Unusually large and clear oscillograms afford much interesting qualitative information as to the influence of space charge travel on corona.