Using magnetic pulse shaping to reduce spark gap losses and electrode erosion

Spark gap electrode erosion is due, in part, to the product of gap voltage and current. As the spark gap breaks down, the initial voltage has not fully dropped before the current begins to rise, and the VI product in this initial phase can be quite high. If the current can be delayed until the discharge channel is fully formed, and the voltage has dropped, the VI product can be significantly reduced. In previous studies on spark gap electrode erosion, one of the parameters was to include magnetic pulse shaping [1]. A significant reduction in erosion resulted from using a saturable reactor to delay the initial current through the gap. Recently, the same method was applied to a vacuum switch, and the turn-on and recovery characteristics of the switch were improved [2]. Based on these findings, further studies will be conducted to explore the connection between magnetic pulse shaping and spark gap erosion and operating parameters. The work will focus on the loss mechanisms in the turnon stage of spark gaps. This paper will describe the initial effort of the experiment, including the test arrangement, diagnostic techniques, and preliminary data.