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Description
Recent trends in the further development of pulsed power technology are towards higher power, longer duration and more compact structures. Compact pulsed power generators based on a Tesla transformer, configured using coaxial pulse forming lines, are widely used in the application of pulsed power systems. Limited by the low permittivity of the traditional energy storage medium (transformer oil), the typical output pulse duration is several nanoseconds for a 1 m length. For this reason, a high permittivity energy storage medium is proposed to replace transformer oil, in order to increase the duration of the output pulse. Propylene carbonate, due to its high relative permittivity of 65, high dielectric insulating strength and low freeing point of -50°C, has great potential as an energy storage medium for pulsed power systems. In this paper, the high permittivity liquid dielectric and a spiral structure are adopted to lengthen the pulse width of a compact pulsed power generator. Firstly, the operational principles of the compact pulsed power generator are described. The techniques used to lengthen the pulse width are then presented and analyzed. Prior to its use, the propylene carbonate was purified by filtering to remove particles, de-ionizing, and de-gassing. The high voltage insulation was designed using insulation matching to ensure optimal distribution of the electromagnetic field. Finally, a compact pulsed power generator with longer output pulse duration was developed. For a generator length of 1 m, an output voltage of 100 kV was developed across a 30 Ω resistive load, with a pulse duration of 33 ns. This paper sets the foundations for the future development of compact pulsed power generators using propylene carbonate as an energy storage medium.
