Energy transfer efficiency of nano-seconds pulsed power generator for nonthermal plasma processing technique

Development of a high voltage nano-seconds pulsed power generator (NS-PG) is attracting attentions from plant manufacturing makers since it enables higher energy efficiencies of plasma processing: such as pollution control, ozone generation and so on. The pulsed power system developed in this study consisted of a pulsed charging circuit, the NS-PG, and a load. The NS-PG consisted of a high-pressure spark gap switch (SGS) as a low inductance self-closing switch, a triaxial Blumlein line as a pulse-forming line, and a voltage transmission line from the Blumlein line to load. The SGS was filled with SF₆ gas, and the output voltage of the generator is regulated by varying the pressure of SF6. The pulse duration of output voltage is 5 ns. In this study, energy transfer efficiency from NS-PG to load is investigated for both positive and negative voltage polarities. In addition, experiments were carried out using a low inductance resistor and a discharge reactor as connected load. The results showed maximum energy transfer efficiency was 85.2% in case of a low inductance resistive load, and 56.7% in case of a discharge reactor. Further efficiency can be achieved by impedance matching the discharge reactor to the NS-PG.