Volumetric Electric Charge Dissipation after Streamer Corona by EFISH and Probe Measurements*

The aim of this work is to study the dynamics of volumetric electric charge deposited by a single pin electrode streamer corona in atmospheric air. Recent studies show that the electric charge remaining on a dielectric surface or in space after the first pulse significantly affects electric field distribution and morphology of followed discharges [JPhD 48 465201; PSST 25-6 20168]. In this study, two methods were employed to measure the electric potential redistribution during and after dissipation of the pulsed 100kV streamer corona: electrostatic probes and the EFISH method (Electrical Field Induced Second Harmonic). It was found that the volumetric charge of a positive pulse polarity occupies a zone up to 100mm from the pin electrode. The followed applied voltage of a negative polarity leads to a partial neutralization of the previous charge and to a generation a layer with high-amplitude electric field. This layer prevents the propagation of the streamers at the next positive polarity pulse. In the case of negative first pulse, the discharge develops differently by way of reducing the streamers length in the first phase of propagation. Application of two independent methods allowed inside the details of steamer discharge dynamics at alternating polarity waveform.