Investigation on discharge process and switching characteristics of a pseudospark switch in series with a magnetic switch

Abstract

To reduce the commutation loss of the pseudospark switch, we connect a magnetic switch in series to the anode of the pseudospark switch. Herein, the typical discharge process and switching characteristics of a pseudospark switch in series with a magnetic switch are experimentally investigated at a different number of magnetic cores, gas pressures, and applied voltages. The results show that the addition of the magnetic switch extends the duration of the hollow cathode discharge of the pseudospark. Moreover, the rapid increase of the loop current and the fast decrease of the discharge voltage are separated, which is beneficial for reducing the commutation loss. With an increasing number of magnetic cores, the magnetic delay time increases and the commutation loss significantly decreases. However, the trigger delay time hardly changes since the magnetic switch does not affect the development of the pre-breakdown phase. At a fixed applied voltage, the trigger delay, magnetic delay time, and commutation loss decrease with increasing gas pressure. Furthermore, at a fixed gas pressure, the trigger delay of the pseudospark switch in series with a magnetic switch first decreases and then remains unchanged with increasing applied voltage, which is similar to that of a pseudospark switch without a magnetic switch because of the strong enough trigger injection. The magnetic delay time decreases and the commutation loss almost linearly increases with increasing applied voltage.

Investigations on enhanced plasma expansion in pseudospark discharge assisted by a magnetic switch

“…The series-connected MS has been successfully introduced to improve the performances of the low-pressure parallel-plate switch by Lauer [10], the thyratron by Weiner [11], the vacuum spark gap by Dougal [12], the pseudospark switch by Frank and Ding et al [13][14][15]. Though the effectiveness in reducing the electrode erosion and commutation loss has been verified in a variety of pulsed power systems, the mechanisms of how the MS affects the discharge process of these switches are lack of in-depth investigations.…”

“…Nevertheless, the commutation loss and the concentrated electrode erosion around the central holes still hamper its performances and further uses, which become more serious at a high repetition rate. In previous work, the influence of the MS on the performances of the pseudospark switch has been thoroughly investigated, and a significant reduction of commutation loss was observed, especially at lower gas pressure [14,15]. However, the problem that how the MS influences the discharge plasma and thereby reduce the electrode erosion remains unsolved.…”