Performance of a Multigap Multiaperture Pseudospark Switch in Series With the Saturable Inductor

Abstract

In this study, experimental investigation has been performed for discharge characteristics of a multigap multiaperture (MGMA) configuration of pseudospark switch (PSS) with a saturable inductor (SI) in series at the anode. The impact of the number of inductor cores on the commutation process is studied experimentally. Initially, in the commutation process, when the anode voltage is 40 kV with five toroid cores, the inductor is unsaturated, and it offers high impedance, resulting in a slow current rise rate of <inline-formula xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink"> <tex-math notation="LaTeX">$\approx 2.5$ </tex-math></inline-formula> kA/ <inline-formula xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink"> <tex-math notation="LaTeX">$\mu \text{s}$ </tex-math></inline-formula> with fast voltage drop rate. During the second phase, when the inductor gets saturated and offers low impedance, it leads to a fast-current rise rate of <inline-formula xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink"> <tex-math notation="LaTeX">$\approx 4.35$ </tex-math></inline-formula> kA/ <inline-formula xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink"> <tex-math notation="LaTeX">$\mu \text{s}$ </tex-math></inline-formula> . Due to the SI, the discharge current rise lags behind the breakdown voltage drop of MGMA-PSS. It results in a significant reduction in power dissipation across the switch during the commutation process. Furthermore, equivalent electrical circuit modeling has also been proposed for the estimation of power losses during the commutation process. During the application of 40-kV anode voltage with five inductor cores at 30-Pa background H2 gas pressure, the commutation losses have been reduced up to ≈95%, which also enhanced the performance of PSS. The proposed analysis and optimization of the inductor core would be very much useful for the reduction in the anode erosion and improved the switching performance of the MGMA-PSS.